a proposed five storey school building with the use of fly ash

8/16/2019 A Proposed Five Storey School Building With the Use of Fly Ash

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A Proposed Five-Storey School Building with the Use of Fly Ash as an Additive

Material for Portland Cement at St. Anthony School, San Andres, Manila

Project By

Magcaleng, Kenneth Rogie D.

Mallillin, John Eric A.

Punzalan, Jan Jhonnel T.

Submitted to the School of Civil, Environmental and Geological Engineering

(SCEGE)

In Partial Fulfillment of the Requirements

For the Degree of Bachelor of Science in Civil Engineering

Mapua Institute of Technology

Muralla St., Intramuros, Manila City

December 2012


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Executive Summary

Availability of rooms such as classrooms is one of the major problems arising on

schools. Escalating number of population with increasing number of school children

enrollees is one of the main factors of lack of classrooms.

With this project, we were given the opportunity to provide a design of a private

school building for the surrounding and nearby residents of San Andres, Manila. Thedesign of a five-storey school building includes fly ash material added to mortars to

minimize the cost of materials in mixing the cement, day lighting that will be considered

and ventilation system in the corridor part of the building in order to minimize the used ofenergy. The said project provides from an existing of 12 up to 28 numbers of classrooms.

There will be an auditorium constructed at the fifth floor of the building. This project will

decongest the classrooms of the main private school building and give comfortable

learning facility to the students and public school teachers as well.


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Table of Contents

Chapter 1: Introduction 1Chapter 2: Presenting the Challenges 2

2.1 Problem Statement 2

2.2 Project Objective 3

2.3 Design Norms Considered 3

2.4 Major and Minor Areas of Civil Engineering 4

2.5 The Project Beneficiary 4

2.6 The Innovative Approach 4

2.7 The Research Component 5

2.8 The Design Component 5

2.9 Sustainable Development Concept 6

Chapter 3: Environmental Examination Report 7

3.1 Project Description 7

3.1.1 Project Rationale 7

3.1.2 Project Location 7

3.1.3 Project Information 8

3.1.4 Description of Project Phases 9

3.1.5 Pre-construction/Operational Phase 9

3.1.6 Construction Phase 9

3.1.7 Operational Phase 10

3.1.8 Abandonment Phase 11

3.2 Description of Environmental Setting and Receiving 12

Environment 3.2.1 Physical Environment 12

3.2.2 Biological Environment 12

3.2.3 Socio-Cultural, Economic and Political Environment 12

3.2.4 Future Environmental Conditions without the Project 13


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3.3 Impact Assessment and Mitigation 13

3.3.1 Summary Matrix of Predicted Environmental

Issues/Impacts and their Level of Significance at

Various Stages of Development 13

3.3.2 Brief Discussion of Specific Significant

Impacts on the Physical and Biological Resources 14

3.3.3 Brief Discussion of Significant Socio-economic

Effects/Impacts of the Project 15

3.4 Environmental Management Plan 16

3.4.1 Summary Matrix of Proposed Mitigation and

Enhancement Measures, Estimated Cost

and Responsibilities 16

3.4.2 Brief Discussion of Mitigation and

Enhancement Measures 18

3.4.3 Monitoring Plan 19

3.4.4 Institutional Responsibilities and Agreements 20

Chapter 4: The Research Component 21

4.1 Introduction 21

4.2 Review of Related Literature 22

4.3 Methodology 32

Chapter 5: Detailed Engineering Design 34

5.1 Loads and Codes 37

5.1.1 Introduction 37

5.1.2 Codes 37

5.1.3 Dead Loads 38

5.1.4 Live Loads 38

5.1.5 Earthquake Loads 41

5.1.6 Wind Loads 41

5.2 Structural Design 43

5.2.1 Introduction 43


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5.2.2 Beam Design 43

5.2.3 Column Design 43

5.2.4 Slab Design 43

5.2.4.1 One Way Slab 43

5.2.4.2 Two Way Slab 44

5.2.5 Design of Trusses 44

5.2.5.1 Design Consideration 44

5.2.5.2 Design of Howe Truss 48

5.2.6 Design of Foundation 54

5.2.6.1 Introduction 58

5.2.7 Design of Concrete Mix 64

Chapter 6: Budget Estimation 74

Chapter 7: Project Schedule 82

Chapter 8: Promotional Material 86

Conclusion and Summary 88

Recommendation 90

Acknowledgement 91

References 92

AppendicesArticle Type Paper

Beam Design

Column Design

Slab Design

Slump Test

Soil Investigation Report

Worksheet for Design of Concrete

Price List

Compression Test of Flyash Concrete Results

Original Project Report Assessment Sheet by Panel Members

English Editor Assessment and Evaluation Rubric

Accomplished Consultation Forms


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Compilation of Assessment Forms (Rubrics)

Copy of Engineering Drawings and Plans

Copy of Project Poster

Photocopy of Receipts

Relevant Pictures

Other required forms

Student Reflections

Resume of Each Member

List of Tables, Illustrations, Charts or Graphs

Figures

Fig. 3.0 The Vicinity Map of Saint Francis Building 8

Fig. 3.1 Map View of the Location of the Proposed Project 8

Fig. 5.1 Shorter Direction Top Bar 59

Fig. 5.2 Longer Direction Top Bar 60

Fig. 5.3 Shorter Direction Bottom Bar 60

Fig. 5.4 Longer Direction Bottom Bar 61

Fig. 5.5 Shorter Direction Bottom Bar Result 62

Fig. 5.6 Longer Direction Bottom Bar Result 62

Fig. 5.3 Shorter Direction Top Bar Result 63

Fig. 5.4 Longer Direction Top Bar Result 63

Fig. 7.1 Gantt Chart 83

Fig. 7.2 Project Network Diagram 84

Fig. 7.3 Project Calendar 84

Fig. 7.4 Project Team Planner 85

Fig. 9.0 Ratio Between Compressive Strength and Time 88


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Tables

Table 1.0 2010 Census and Housing and Population of

National Capital Region (NCR), Philippines 2 2

Table 3.1 Summary Matrix of PredictedEnvironmental Issues/Impacts and their

Level of Significance at Various Stages of Development 14

Table 3.2 Summary Matrix of Proposed Mitigation and

Enhancement Measures, Estimated

Cost and Responsibilities 16

Table 3.3 Monitoring Plan 20

Table 5.3 Support Reactions End Forces 49

Table 5.4 Member End Forces 49

Table 5.5: Summary of Concrete-Mix Parameters

from Material Testing 70

Table 5.6 A tabulated Summary of computed values is shown below: 73


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Chapter 1

Introduction

Educational problems in the Philippines have gone through many changes and

developments for the past few years. The continuous process made great impact in the

lives of millions of Filipinos. Relatively, the changes have given both advantages and

disadvantages, the latter causing the downfall of many people. There are numerous

questions concerning the issues and problems existing in the Philippine educational

system as to how to attain the kind of quality of education that Filipinos have been

searching and longing for.

The high cost of materials in construction hampered the efforts of different

institutions to build new structures. Learning institutions such as schools have small

budgets from the government because of the need to fund various other priorities.

On the other hand, the private sector in the country has been a major provider of

educational services, accounting for about 7.5% of primary-school enrollment, 32% of

secondary-school enrollment and about 80% of tertiary-school enrollment. Private

schools have proven to be efficient in resource utilization. Per unit costs in private

schools are generally lower when compared to public schools. This situation is more

evident at the tertiary level. Government regulations have given private education more

flexibility and autonomy in recent years, notably by lifting the moratorium on

applications for new courses, new schools and conversions, liberalizing the tuition fee

policy for private schools, replacing values education for third and fourth years with

English, mathematics and natural science at the option of the school, and issuing a

revised manual of regulations for private schools last August 1992.

In the school year 2001/02, there were 4,529 private elementary schools (out of a

total of 40,763) and 3,261 private secondary schools (out of a total of 7,683). In 2002/03,

there were 1,297 private higher education institutions (out of a total of 1,470).


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Chapter 2

Presenting the Challenges

2.1

Problem Statement

The area of San Andres, Manila is composed mostly of residential sections with

some sections classified as commercial. Students from Paco and Malate study at the

school here because it is one of the well-known elementary and secondary schools in

Manila. Although the population of Manila (from the table 1.0) does not increase

significantly, the numbers of student enrollees has grown further as stated (table1.1).

Table 1.0 2010 Census and Housing and Population of National Capital Region (NCR),

Philippines

Region/Province/Highly

Urbanized City

Total Population Population Growth

Rate

l-May-90 l-May-00 l-May-10 1990-

2000

2000-

2010

1990-

2010

Philippines 60,703,810 76,506,928 92,337,852 2.34 1.90 2.12

National Capital Region 7,948,392 9,932,560 11,855,975 2.25 1.78 2.02

City of Las Pinas 297,102 472,780 552,573 4.75 1.57 3.15

City of Makati 453,170 471,379 529,039 0.39 1.16 0.78

City of Malabon 280,027 338,855 353,337 1.92 0.42 1.17

City of Mandaluyong 248,143 278,474 328,699 1.16 1.67 1.41

City of Manila 1,601,234 1,581,082 1,652,171 -0.13 0.44 0.16

City of Marikina 310,227 391,170 424,150 2.34 0.81 1.58

City of Muntinlupa 278,411 379,310 459,941 3.14 1.95 2.54

City of Navotas 187,479 230,403 249,131 2.08 0.78 1.43

City of Paranaque 308,236 449,811 588,126 3.85 2.72 3.28

City of Pasig 397,679 505,058 669,773 2.42 2.86 2.64


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City of San Juan 126,854 117,680 121,430 -0.75 0.31 -0.22

City of Valenzuela 340,227 485,433 575,356 3.62 1.71 2.66

Caloocan City 763,415 1,177,604 1,489,040 4.43 2.37 3.39

Pasay City 368,366 354,908 392,869 -0.37 1.02 0.32

Pateros 51,409 57,407 64,147 1.11 1.12 1.11

Quezon City 1,669,776 2,173,831 2,761,720 2.67 2.42 2.55

Taguig City 266,637 467,375 644,473 5.77 3.26 4.51

2.2. Project Objective

The main objective of this project is to study and design a five-storey building to

be constructed with low cost and efficient materials that conform to the standards and

specifications on building construction. This includes the day lighting system that can

minimize expenses for electricity. An eco-friendly ventilation system will also be added

to reduce the cost of energy.

2.3 Design Norms Considered

Efficiency in cost is one of the design norms of the proposal. It should beconsidered because the main purpose of this project is to reduce the expenses for building

construction and decrease energy dependency. Sustainability will be achieved through its

collaboration with green engineering.

The stability of the structure is one of the important design norms. It should meet

the desired standards and specifications in order to be strong and resilient against

earthquakes and disasters.

Spacing is also a design norm since students need more space to enable them to

relax and to promote ease of movement. Spacing is very important in order to allow

students to concentrate on their work and activities. This will enable their knowledge to

improve and accelerate their effective learning with their teachers.


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2.4 Major and Minor Civil Engineering Fields

The civil engineering areas to be covered are structural, construction and

geotechnical engineering. Structural engineering will focus on the superstructures. For

construction engineering, it will focus on the materials needed in construction. It will

emphasize the mixtures of the materials that can be alternatives source of materials on the

making of the cement. Environmental engineering will focus on the design of the energy

efficiency of the building. With the combination of natural lighting effects and an

ecofriendly ventilation system, this project will help keep nature at an ecological

balanced state.

2.5 The Project Beneficiary

Saint Anthony School is the selected beneficiary since the number of student

enrollees continues to increase. On the other hand the availability of classrooms is

limited. The availability of land to be acquired and on which can be built new facilities is

very minimal since nearby areas are already occupied by mixed residential and

commercial establishments.

The school director decided to choose Saint Francis Building since the current

school building consists of only three floors. But the current building needs to be

demolished because of the quality and stability conditions of the structure. This will give

way to a new and higher structure.

With the addition of new facilities such as classrooms and laboratories, the

learning activities of the students will continue and the project can be an inspirational

model to the other public and private schools.

2.6 Innovative Approach

In this project, the help of different technological developed programs and software

was needed to make the project possible and to better improve the design and plan. The

following tools were used:


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ETABS

This program is an integrated model that computes moment resisting frames,

frames with reduced beam sections or side plates, rigid and flexible floors,

composite or steel joist floor framing systems, etc.

AutoCAD

This program helped in the detailed drawing and laying out of the plan and

specifications of the project. This included the architectural and structural plan.

STAADPro

This software application program eased the design and analysis of members and

checked the adequacy and stability of the structures.

2.7 Research components

The materials that will be used in the construction of the school building will be

made of a combination of cement and fly ash for concreting. The materials were

examined for a comparative analysis of the cost and quality of low cost materials and

conventional materials.

The right placing of windows in corridors that maximize air flow was emphasized

with the use of metal louvers (used to control the daylight condition for energy savings).

Energy efficient methods of air circulation were examined in order to supply fresh air to

the building.

2.8 Design components

These were the following:

Substructure

It covered the design of foundations, their footing and the adequacy of the

load capacity of the structure with the limited settlements of the soil.

Superstructure


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The superstructure will be composed of reinforced concrete beams,

columns and slabs. The design depended on such loads as weight, superimposed

and seismic. NSCP 2010 and UBC were used.

Roofing design

Every member of the truss was planned and analyzed because of the

factors that may affect the condition of the roofs. Wind loads, dead loads and roof

live loads were consequently designed with precision and accuracy.

2.9 Sustainable Development

As the number of school children continues to increase, more facilities such as

classrooms are also needed. Building structures incorporated with low cost materials such

as combining alternative materials will pave the way for the encouragement of different

learning institutions. The reduced expenses of the proposed project will help since

alternative materials will be applied instead of conventional materials which cost more.

Naturally ventilated buildings feel more comfortable than ones that are air

conditioned. But the site of the building, with factors such as topography and the

proximity of other buildings and main roads, may well prevent this from being feasible.


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Chapter 3

Environmental Examination Report

3.1 Project Description

3.1.1 Project Rationale

San Andres is a district located in the south east of the City of Manila. Although it

only has a small land area, it is the second most densely populated district in Manila after

Tondo. The district is home to two private schools, St. Scholastica's College and St.

Anthony School. In order to alleviate overcrowding and accommodate the growing

school population, it was proposed to study the design and construction of a five-storey

school building at St. Anthony School that is both an eco-friendly sustainable structure

and structurally stable. The aim of this project is to provide a place for comprehensive

education that will support each individual in society to achieve their potential as a

human being. It will also equip the students with the skills to maintain a healthy and productive existence, to grow into resourceful and socially active adults, and to make

cultural and political contributions to their communities.

3.1.2 Project Location

St. Anthony School at San Andres, Manila is the chosen site since the school

needs improvement in the upgrading the facilities due to its old structural stability and to

accommodate more students and teachers. (See tables 2.1 & 2.2.)


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3.1.3 Project Information

The project is a design of a five-storey school building and will be located in

Singalong St., St Anthony School, San Andres, Manila. It will be an eco-structure

because it will be made of sustainable low cost materials. It will be one of the most

economical designs and be made of cheap and alternative materials that will be funded by

the private school. Air ventilation along corridors will be built according to the plan.

Figure 3.0 The vicinity map of Saint Francis Building

Figure3.1 Map view of the location of the Proposed Project

Saint Francis

Building


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3.1.4 Description of Project Phases

The project will have four phases: pre-construction/operational, construction

phase, operational and abandonment. The pre-construction/operational phase includes the

things to be done before the project starts; it is the preparation before the construction and

operational phases. The construction phase includes the preparation of the site and

construction of the structure. The operational phase of the project discusses how it

operates or works. And lastly the abandonment phase discusses what should be done with

the project if it is unoccupied.

3.1.5 Pre-construction/Operation phase

3.1.5.1 Preparation of Construction Documents

Construction documents are part of the legal contract between the property owner

and general contractor.


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3.1.5.2 Design review and commentary

To identify design conflicts as part of a pre-construction constructability review.

3.1.5.3 Construction phasing, sequencing and site logistics

Construction planning includes site investigation, site management, obtaining

permits, scheduling, excavation planning, estimating, value engineering and quality

control.

3.1.6 Construction phase

3.1.6.1 Clearing and Grubbing

Clearing and grubbing consists of removing all objectionable materials from

within the work site.

3.1.6.2 Excavation

Excavation of soil by cut and fill is needed in order to place the sub-structure or

the foundation itself.

3.1.6.3 Building Structure

This consists of the construction of the footing, beams, slabs, columns and walls.

3.1.6.4 Water and Sewer Lines

This is the construction of pipe lines for water supply and sewer drainage lines.


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3.1.7 Operational Phase

3.1.7.1 Framing

Framing is a building technique based around structural members, usually

called studs, which provides a stable frame to which interior and exterior wall coverings

are attached.

3.1.7.2 Insulation and Sheetrock

Insulation and Sheetrock is done after framing and mechanical inspections are

finished. After insulation and sheetrock taping, bedding and texturing of the interior walls

can be started.

3.1.7.3 Flatworks

Flatworks can be done simultaneously while the structure is nearly in completion.

Flatworks include any patios, all sidewalks and driveways.

3.1.8 Abandonment Phase

3.1.8.1 Removal of Waste

During construction, demolition and land clearing debris results from construction

activities; these materials can be recycled, reused or salvaged. The proper disposal of

waste is necessary.


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3.1.8.2 Dismantling of Structures and Equipment

After the dismantling of equipment and structures, restoration plans are to be put

out, some of these are re-vegetation, leveling and backfilling, and the repair of road

networks.

3.2 Description of Environmental Setting and Receiving Environment

3.2.1 Physical Environment

The location of the proposed project is surrounded mostly by residential structures

and some commercial establishments and also it is accessible due to the nearby roadways.

The area of the project location has minimal space therefore a small portion of the

quadrangle inside the school is enough to re-construct a five-storey school building. The

size of the lot is 680.93 square meters. The project will maximize the size of the available

area by adding new rooms, laboratories and an auditorium.

3.2.2 Biological Environment

Within the area, there is a garden beside the existing building. Vegetation living

in the vicinity is absent because of unplanned zoning. Different establishments have

sprouted in the area. Roads and pathwaysare made up of concrete and only a few trees are

present which means animal and plant life are not concerns to address. The atmospheric

condition in the area is impaired due to the pollution produced by the vehicles in the

roads near the site.

3.2.3 Socio- Cultural, Economic and Political Environment

In the social aspect, a school is going to be built, wherein lively relationships

between individuals may therefore be formed and, likewise, the said institution covering

primary and secondary education can therefore instill the Filipino value of giving high


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importance to education. In the economic aspect, by applying modern techniques like the

use of natural day lighting and constructing well ventilated facilities, expenses for energy

can be reduced in the near future. In addition, the project will promote employment

within the area and those who live near the area. Other than that, additional facilities like

classrooms, laboratories, and an auditorium will help the quality of education of the said

institution.

3.2.4 Future Environmental Conditions without the Project

There would be no significant change in the environmental condition with/without

the construction of the proposed project; in climate, atmosphere, etc. since there is a

small amount of plants within the location, with the construction of the project there

would be a minimal impact on the environment due to replacing the existing three-storey

school building.

3.3 Impact Assessment and Mitigation

3.3.1 Summary Matrix of Predicted Environmental Issues/Impacts and their Level

of Significance at Various Stages of Development


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Table 3.1 Summary Matrix of Predicted Environmental Issues/Impacts and their Level of

Significance at Various Stages of Development

Predicted Environmental

Issues/ImpactsLevel of Significance

Water Quality Low Impact

Air Quality Low Impact

Noise Pollution Low Impact

Waste Generation Moderate Impact

Population Density High Impact

3.3.2 Brief Discussion of Specific Significant Impacts on Physical and Biological

Resources

3.3.2.1 Existing Land Uses

The proposed site for constructing a new building is a three-storey existing

building that will be demolished first before a new one can be built.

3.3.2.2Atmospheric Condition

The atmospheric condition in the area is not at its best condition. The quality of

the present atmospheric condition has been impaired because the site is situated near the

main roads of San Andres, Manila.


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3.3.3 Brief Discussion of Significant Socio-economic Effects/Impacts of the Project

Since the major purpose of this project is to accommodate more students in St.

Anthony School, it will greatly improve the education occurrence of the residents of San

Andres Manila by adding more facilities such as laboratories and an auditorium to the

proposed project.


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3.4 Environmental Management Plan

3.4.1 Summary Matrix of Proposed Mitigation and Enhancement Measures,

Estimated Cost and Responsibilities

Table 3.2Summary Matrix of Proposed Mitigation and Enhancement Measures,

Estimated Cost and Responsibilities

Impact Mitigation Responsibilities

Water Quality

• Proper surface and ground drainage,

• Conservation of water during construction

phase to ensure efficient water use.

Contractor

Air Quality

• Site and stock pile enclosure (sand

stockpiles and tiles boxes were enclosed once

on-site);

• On-site mixing in enclosed or shielded areas

(Mixing of small quantities of materials was

done in the open air near the respective

works);

• Proper unloading operations (piled

curbstone and sand piles, no recorded

accidents), manual transport of materials on-

site, no heavy trucks were allowed to enter

into the construction area;

• Keeping hauling routes free of dust andregularly cleaned through water spraying after

each activity;

• Construction safety nets were used to

prevent dust from reaching and affecting

Contractor


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pedestrians;

• Water was frequently sprayed to reduce dust

dispersion.

Water Quality

• Surface water and groundwater are notexpected to be affected by the project

activities since the paint used is water-based

(as an alternative to petroleum solvents);

• Oil and lubricants from vehicles and

machinery are considered negligible since the

on-site use of machinery is not significant.

Contractor

Noise Pollution

• limiting the noisiest construction activities

to daytime hours to the greatest extent

possible

• building permanent noise barriers during the

early phases of construction (where

construction sequencing allows) in order to

reduce noise levels.

Contractor

Waste

Generation

• Waste transport and disposal at designated

disposal sites (integrated solid waste

management).

• Construction wastes are collected in isolated

areas and disposed of according to declared

collection schedules.

Contractor

Population

Density

• Use of construction safety nets for public

safety.Contractor


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3.4.2 Brief Discussion of Mitigation and Enhancement Measures

3.4.2.1 Mitigation Measures for the Project Design

3.4.2.1.1 Dust Production

To prevent dust along roadways, circulation and access roads used by the

collection trucks should be paved. To prevent dust from the unloading of wastes in the

facility, a high quality paving capable of withstanding frequent truck traffic should be

used to cover the receiving area.

3.4.2.1.2 Public Hazards

Proper fencing at a minimal height of three meters around the whole site should

be ensured in order to prevent unauthorized access to the facility.

3.4.2.2 Mitigation Measures for the Construction Phase

During the construction phase, it is essential to adopt strategies to prevent or

minimize dust emissions, noise generation, health and safety hazards, and negative

impacts related to the generated construction wastes. The main control measures should

be included within the construction contracts and be considered as requirements from

contractors.

3.4.2.2.1 Noise and Dust Emissions

The major mitigation measures required to reduce noise and dust emissions are

mainly during the construction phase. The recommended mitigation measures for dust

emissions are on-site mixing and unloading operations, and ensuring adequate

maintenance and repair of construction machinery.


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Table3.3 Monitoring Plan

Impact Measure Monitoring

Air Quality Masks Daily

Noise Pollution Noise Control Weekly

Waste Generation Check of waste Daily

Population Crowd control Daily

3.4.4 Contingency Plan

In the duration of the construction, the construction area, just like any other

construction project, will have a safety area that will have every first aid material that

may be needed and someone who knows how to perform first aid. Also in the duration of

project construction and even after construction, there should be assured safety by having

emergency measures and equipment like fire extinguishers and alarms.

3.4.5 Institutional Responsibilities and Agreements

To be built is an environment-friendly structure that will serve as a school that

will offer primary education. For the proponent’s institutional responsibilities and

agreements, it was agreed to make it a point to consider the environmental effects of this

project as well as the structural codes to be followed and to therefore comply with the

requirements of the local government in the case of building an establishment in the

vicinity. It was made a point to coordinate with the local government, DENR

(Department of Environment and National Resources) and DEPED (Department ofEducation) to have guidelines to follow and to be monitored for the betterment of both

the owner of the project and the people that surround the area.


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Chapter 4

4. Research Component

4.1 Introduction

A large number of innovative alternative building materials and low cost

construction techniques have been developed through intensive research efforts during

the last three to four decades that satisfy functional as well as specification requirements

of conventional materials/techniques and that provide ways of bringing down

construction costs. Fly ash, an industrial by-product from thermal power plants with a

current annual generation of approximately 108 million tones and with proven suitability

for a variety of applications as admixture in cement/concrete/mortar, lime pozzolana

mixture (bricks/blocks) etc., is such an ideal material that attracts a lot of attention. Fly

ash utilization in building materials has many advantages, like cost effectiveness, being

environmental friendly, increases in strength, and the conservation of other natural

resources and materials.

Fly ash or pulverized fuel ash, an artificial pozzolana, is the residue from the

combustion of pulverized coal used as fuel. During the combustion of coal, the products

formed are classified into two categories, viz. bottom ash and fly ash. The bottom ash is

that part of the residue which is fused into particles. Fly ash is that part of the ash which

is entrained in the combustion gas leaving the boiler. Most of this fly ash is collected in

either mechanical collectors or electrostatic precipitators.

Fly ash is disposed of either by dry or wet systems. Most power plants in India

use the wet disposal system. Different types of coal produce different quantities of ash,

depending on the concentration of mineral matter in the respective types of coal. In India

the coal contains a very high percentage of rock and soil and therefore the ash contents

are as high as 50%.


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Ash may be classified into two groups as Class C and Class F, based on the nature

of their ash constituents. One is bituminous ash (Class F) and the other is the lignite ash

(Class C). Lignite ashes contain more calcium oxide and magnesium oxide than ferric

oxide, but bituminous ash contains more ferric oxide than calcium and magnesium

oxides. The average particle size of lignite fly ash is considerably coarser than the

bituminous variety. Also free lime is present in all the lignite fly ashes. The lignite ash

(Class C) in India is produced at Neyveli Thermal Power Plant and the most of the other

power plants in India produce bituminous ashes (Class F).

4.2 Review of Related Literature

4.2.1 Fly Ash

Fly ash is a byproduct of coal burning power plants and is classified as pozzolan.

The particles of fly ash are spherical in shape, generally finer than cement. Fly ash in

bulk is very similar to cement in its appearance and its physical and chemical properties

(ASCC & ACI).

When used in cement in concrete mix, fly ash reacts with calcium hydroxide, a

chemical by product of cement hydration, producing the same binder as Portland cement.

Through this “pozzolanic” reaction, fly ash is a part of the total cementitous material.

When fly ash is used in concrete it is usually replace part of the Portland cement content.

Because reactions vary, the mix must be proportioned specifically for the cement and fly

ash being used (ASCC & ACI).


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4.2.2High-Volume Fly Ash Concrete

Fly ash, a principal by-product of coal-fired power plants, is well accepted as a

pozzolanic material that may be used either as a component of blended Portland cements

or as a mineral admixture in concrete. In commercial practice, the dosage of fly ash is

limited to 15%-20% by mass of the total cementitious material. Usually, this amount has

a beneficial effect on the workability and cost economy of concrete but it may not be

enough to sufficiently improve the durability to sulfate attack, alkali-silica expansion, and

thermal cracking. For this purpose, larger amounts of fly ash, on the order of 25%-35%

are being used.

Although 25%-35% fly ash by mass of the cementitious material is considerably

higher than 15%-20%, this is not high enough to classify the mixtures as High Volume

Fly Ash (HVFA) concrete according to the definition proposed by Malhotra and Mehta.

From theoretical considerations and practical experience it has been determined that, with

50% or more cement replacement by fly ash, it is possible to produce sustainable, high-

performance concrete mixtures that show high workability, high ultimate strength, and

high durability.

4.2.3High Performance Concrete

The characteristics defining an HVFA concrete mixture are as follows:

• A minimum of 50% of fly ash by mass of the cementitious materials must be

maintained.

•

Low water content, generally less than 130 kg/m,3 is mandatory.

• Cement content of generally no more than 200kg/m3 is desirable.

• For concrete mixtures with specified 28-day compressive strength of 30 MPa or

higher, slumps >150 mm, and water-to-cementitious materials ratio of the order of


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0.30, the use of high-range water-reducing admixtures (superplasticizers) is

mandatory.

• For concrete exposed to freezing and thawing environments, the use of an air-

entraining admixture resulting in adequate air-void spacing factor is mandatory.

• For concrete mixtures with slumps less than 150 mm and 28-day compressive

strength of less than 30 MPa, HVFA concrete mixtures with a water-to-

cementitious materials ratio of the order of 0.40 may be used without

superplasticizers.

4.2.4 Characteristics of Fly Ash

Fly ash is a diverse substance. The characteristics of fly ash differ depending on

the source of the coal used in the power plant and the method of combustion.

Cenospheres, hollow spherical particles as part of fly ash, are believed to be formed by

the expansion of C02 and H20 gas, and evolved from minerals within the coal being burnt.

The predominant forces are, however, the pressure and surface tension on the melts, as

well as gravity. The predominantly spherical microscopic structure of fine fly ash is

related to the equilibrium of the forces on the molten inorganic particle as it is forced up

the furnace or smoke stack against gravity. The molten inorganic particles cool down

rapidly, maintaining their equilibrium shape. A similar situation is found in spherical

drops of water falling from a faucet.

Because cenospheres are hollow, they have a low bulk density. The percentage of

cenospheres increases with the ash content in the coal, and decreases with the

concentration of Fe203. This indicates that Fe2C>3 is concentrated in the higher density

fraction of fly ash, which is to be expected from the high density of Fe 203 (5.25 g/cm3)

and Fe304 (5.17 g/cm

3

). The iron species should not contribute significantly to theinfrared spectra.

The inorganic material is entrained over years in the coal melt during the

combustion of coal in the furnace, and with some, but limited, fusing of the molten

particles. Some of the vaporized low boiling elements, for example alkali metal salts,


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coalesce to form submicron particles. Some of the vaporized compounds, most notably

the polynuclear aromatic hydrocarbons and polycyclic aromatic hydrocarbons, adsorb

onto the surface of the fly ash particles. The surface of fly ash particles is, therefore,

commonly enriched in carbon, potassium, sodium, calcium and magnesium

4.2.5 Advantages and Disadvantages of Fly Ash

4.2.5.1 Advantages

Fly ash improves concrete workability and lowers water demand. Fly ash particles

are mostly spherical tiny glass beads. Ground materials such as Portland cement are solid

angular particles. Fly ash particles provide a greater workability of the powder portion of

the concrete mixture which results in greater workability of the concrete and a lowering

of water requirement for the same concrete consistency. Pump ability is greatly enhanced.

1. Low water/cement ratio

2. Low permeability

3. Resistance to sulfate

4. Minimization of alkali-silica reaction

5. Minimum segregation

6. Decreasing in heat of hydration

7. İncreasing the strength

8. Smooth concrete surface

9. Perfect concrete rheology

10.

Environment-friendly

Fig. 3.1 Compressive Strength of Fly Ash Concrete and Conventional Concrete


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Source: A Ground Breaking Presentation to the Management Association of The Philippines by EJ

Fransman of SAPTASCO- Septeber 2009

4.2.5.2 Disadvantages

1.

Slower strength gain2. Longer setting times

3. Air content control

4. Seasonal limitations

5. Color variability

The structural effects of fly ash may be more critical, but cosmetic concerns also

affect its use in concrete. It is more difficult to control the color of concrete containing fly

ash than mixtures with Portland cement only. Fly ash also may cause visual

inconsistencies in the finished surface, such as dark streaks from carbon particles.


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4.2.6 Mechanisms by which fly ash improves the properties of concrete

A good understanding of the mechanisms by which fly ash improves the

rheological properties of fresh concrete and ultimate strength as well as the durability of

hardened concrete is helpful to insure that potential benefits expected from HVFA

concrete mixtures are fully realized. These mechanisms are discussed next.

4.2.6.1 Fly ash as a water reducer

Too much mixing-water is probably the most important cause for many problems

that are encountered with concrete mixtures. There are two reasons why typical concrete

mixtures contain too much mixing-water. Firstly, the water demand and workability are

influenced greatly by particle size distribution, particle packing effect, and voids present

in the solid system. Typical concrete mixtures do not have an optimum particle size

distribution, and this accounts for the undesirably high water requirement to achieve

certain workability. Secondly, to plasticize a cement paste for achieving a satisfactory

consistency, much larger amounts of water than necessary for the hydration of cement

have to be used because Portland cement particles, due to the presence of an electric

charge on the surface, tend to form flocs that trap volumes of the mixing water.

It is generally observed that a partial substitution of Portland cement by fly ash in

a mortar or concrete mixture reduces the water requirement for obtaining a given

consistency. Experimental studies by Owen and Jiang and Malhotra have shown that with

HVFA concrete mixtures, depending on the quality of fly ash and the amount of cement

replaced, up to a 20% reduction in water requirements can be achieved. This means that

good fly ash can act as a superplasticizing admixture when used in high-volume. The

phenomenon is attributable to three mechanisms. First, fine particles of fly ash get

absorbed on the oppositely charged surfaces of cement particles and prevent them from

flocculation. The cement particles are thus effectively dispersed and will trap large

amounts of water, which means that the system will have a reduced water requirement to

achieve a given consistency. Secondly, the spherical shape and the smooth surface of fly


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ash particles help to reduce inter-particle friction and thus facilitate mobility. Thirdly, the

“particle packing effect” is also responsible for the reduced water demand in plasticizing

the system. It may be noted that both Portland cement and fly ash contribute particles that

are mostly in the 1 to 45 µm size range, and therefore serve as excellent fillers for the

void space within the aggregate mixture. In fact, due to its lower density and higher

volume per unit mass, fly ash is a more efficient void-filler than Portland cement.

4.2.6.2 Drying shrinkage

Perhaps the greatest disadvantage associated with the use of Portland-cement

concrete is cracking due to drying shrinkage. The drying shrinkage of concrete is directly

influenced by the amount and the quality of the cement paste present. It increases with an

increase in the cement paste-to-aggregate ratio in the concrete mixture, and also increases

with the water content of the paste.

Clearly, the water-reducing property of fly ash can be advantageously used for

achieving a considerable reduction in the drying shrinkage of concrete mixtures.

The significance of this concept is illustrated by the data in Table 2 which shows

mixture proportions of a conventional 25 MPa concrete compared to a superplasticized

HVFA concrete with similar strength but higher slump. Due to a significant reduction in

the water requirement, the total volume of the cement paste in the HVFA concrete is only

25% as compared to 29.6% for the conventional Portland-cement concrete which

represents a 30% reduction in the cement paste-to-aggregate volume ratio.


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Table 2 Comparison of cement paste volumes

Conventional concrete HVFA concrete

kg/m m kg/m m

Cement 307 0.098 154 0.149

Fly ash - - 154 0.065

Water 178 0.178 120 0.120

Entrapped air (2%) - 0.020 - 0.020

Coarse aggregate 1040 0.385 1210 0.448

Fine aggregate 825 0.305 775 0.287

Total 2350 0.986 2413 0.989

w/cm 0.58 - 0.39 -

Paste: volume - 0.296 - 0.254

Percent - 30.0% - 25.7%

4.2.6.3 Thermal cracking

Thermal cracking is a serious concern in massive concrete structures. It is

generally assumed that this is not a problem with reinforced-concrete structures of

moderate thickness, e.g. 50-cm thick or less. However, due to the high reactivity of

modem cements, cases of thermal cracking are reported even from moderate-size

structures made with concrete mixtures of high-cement content that tend to develop

excessive heat during curing. The physical-chemical characteristics of ordinary Portland

cements today are such that very high heat-of-hydration is produced at an early age

compared with that of normal Portland cements available 40 years ago. Also, high-early

strength requirements in modem construction practice are usually satisfied by an increase

in the cement content of the concrete mixture. Further, there is considerable construction

activity now in the hot-arid areas of the world where concrete temperatures in excess of

60°C arc not uncommon within a few days of concrete placement.

For unreinforced mass-concrete construction, several methods are employed to

prevent thermal cracking, and some of these techniques can be successfully used for the


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mitigation of thermal cracks in massive reinforced-concrete structures. For instance, a 40-

MPa concrete mixture containing 350 kg/m1 Portland cement can raise the temperature of

concrete by approximately 55-60°C within a week if there is no heat loss to the

environment. However, with a HVFA concrete mixture containing 50% cement

replacement with a Class F fly ash, the adiabatic temperature rise is expected to be 30-

35°C. As a rule of thumb, the maximum temperature difference between the interior and

exterior concrete should not exceed 25"C to avoid thermal cracking. This is because

higher temperature differentials are accomplished by rapid cooling rates that usually

result in cracking. Evidently, in the case of conventional concrete it is easier to solve the

problem cither by keeping the concrete insulated and warm for a longer time in the forms

until the temperature differential drops below 25°C or by reducing the proportion of

Portland cement in the binder by a considerable amount. The latter option can be

exercised if the structural designer is willing to accept a slightly slower rate of strength

development during the first 28 days, and the concrete strength specification is based on

90-days instead of 28-day strength.

4.2.6.4 Water-tightness and durability

In general, the resistance of a reinforced-concrete structure to corrosion, alkali-

aggregate expansion, sulfate and other forms of chemical attacks depends on the water-

tightness of the concrete. The water-tightness is greatly influenced by the amount of

mixing-water, type and amount of supplementary cementing materials, curing, and

cracking resistance of concrete. High-volume fly ash concrete mixtures, when properly

cured, are able to provide excellent water-tightness and durability. The mechanisms

responsible for this phenomenon arc discussed briefly below.

When a concrete mixture is consolidated after placement, along with entrapped

air, a part of the mixing-water is also released. As water has low density, it tends to travel

to the surface of concrete. However, not all of this "bleed water" is able to find its way to

the surface. Due to the wall effect of coarse aggregate particles, some of it accumulates in

the vicinity of aggregate surfaces, causing a heterogeneous distribution of water in the


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system. Obviously, the interfacial transition zone between the aggregate and cement paste

is the area with high water/cement and therefore has more available space that permits the

formation of a highly porous hydration product containing large crystals of calcium

hydroxide and ettringite. Micro cracks due to stress are readily formed through this

product because it is much weaker than the bulk cement paste with a lower water/cement.

It has been suggested that micro cracks in the interfacial transition zone play an

important part in determining not only the mechanical properties but also the

permeability and durability of concrete exposed to severe environmental conditions. This

is because the rate of fluid transport in concrete is much larger by percolation through an

interconnected network of micro cracks than by diffusion or capillary suction. The

heterogeneities in the micro cracks of the hydrated Portland-cement paste, especially the

existence of large pores and large crystalline products in the transition zone, are greatly

reduced by the introduction of fine particles of fly ash. With the progress of the

pozzolanic reaction, a gradual decrease occurs in both the size of the capillary pores and

the crystalline hydration products in the transition zone, thereby reducing its thickness

and eliminating the weak link in the concrete microstructure. In conclusion, a

combination of particle packing effect, low water content, and pozzolanic reaction

accounts for the eventual disappearance of the interfacial transition zone in HVFA

concrete, and thus enables the development of a highly crack-resistant and durable

product.

4.2.7 Carbon Content of Fly Ash

It has been reported that concrete containing fly ash can be durable to the effects

of freezing and thawing provided it has a stable air-void system. There have been reports

of carbon content in the fly ash reducing the effectiveness of air-entraining agent.

Sturrup, Hooton and Clendennning (1983) found that doubling the carbon content

required a double dosage of air-entraining admixture for entraining about 6.5 ± 1 % air.

They mentioned in their findings that as long as the required air contents are obtained,


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carbon content in the fly ash does not adversely affect the performance of fly ash

concrete vis-a-viz the effects of freezing and thawing.

4.3 Methodology

In order to come up with the design of the project, necessary data were gathered

from the population statistics and economic activity of San Andres, Manila, as well as the

population density of students needed by the school, up to the soil properties of the

proposed school.

After obtaining the necessary information needed for the project, a five-storey

school that can accommodate students of San Andres, Manila was designed. As the

number of students continues to rise, more and more school facilities such as classrooms

are needed by the school.

As the materials are known for the design of the project, initial cost estimation

was done in order to know that the funds can be raised by the school institution. Since the

objective of the proposal is to reduce the cost of the materials used in the design of the

project, the school can afford and utilize them properly.


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Figure 1.0 Flow Chart of Project

START

Data Gathering (populationof students on the location)

Develop Draft Plan

Consultation of Draft Plan

Design Process

Estimation of the Project

END


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Chapter 5

Detailed Engineering Design

Design was conducted according to National Structural Code of the Philippines

2010 Vol. 1. The Ultimate Strength Design approach was used as a design criterion. All

load combinations were entered into the model, and the combined load effects were

compared to the reduced nominal strengths of the members. In addition to analyzing

members under typical load effects, for seismic design, a drift criterion accounting for

plastic deformation was enforced.

The structure was designed for serviceability: Deflections of beams under service

live load are limited to L/240 and story drifts under 50-year wind events (unfactored wind

load) are limited to L/400. A computer model was constructed in ETABS to conduct

three-dimensional frame analysis of the structure. The model included only the main

beams and the columns; the floor beams and decking were designed by hand. Lateral

loads were applied to diaphragms at each floor; diaphragms were assumed rigid as

justified by a diaphragm flexibility study.

Dead, live, roof live and snow loads were calculated in accordance with NSCP

2010. Rain loads were assumed to be negligible compared to the roof live load.

Calculations of gravity loads are included. Dead loads were calculated, including the

weight of all structural components (columns, main beams, floor beams, and floor

system), cladding, and a superimposed dead load of 25 psf on the roof and 15 psf on all

floors.

The LRFD load combinations were used to find maximum compression, tension,

shear force and bending moment in all members. This strength requirement governed

member selection of non-moment frame columns and braces. In these cases, the lightest

members were chosen to resist loads in critical members, and member sections were


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repeated if reasonable. In all other cases, either story drifts or serviceability requirements

governed member selection. Serviceability

A beam deflection criterion of L/240 was used under service live load for all

beams. For all simply-supported beams in the structure, this deflection limitation

controlled the selection. The service wind story drift limitation of L/400 was met and did

not control for any members. This is because the lateral force-resisting system was

already very stiff to handle seismic loads.

According to NSCP 2010 Section 410, analysis included here the investigation of

reinforced concrete beams subject to steel yielding, and decision if it is to be designed as

non-rectangular or rectangular, singly-reinforced or doubly-reinforced concrete beams.

Included here are the determination of strength reduction factor and the steel ratio. Also

included were the axial capacity analysis of columns and the design of ties and vertical

bars.

According to NSCP 2010 Section 411, analysis included here the determination of

size of stirrups and their spacing, and also the investigation if the reinforced concrete has

the capacity to resist shearing forces. Code provisions for design ranges from a simplified

design to a much detailed design when given axial, flexure and shear reaction altogether.

According to NSCP 2010 Section 413, analysis included here the stress spread, and the

design and spacing of steel bars in a two way slab. It facilitates on how the bars would be

placed along the slab using the direct design method. Code provisions set also the

maximum bending moments at each faces of the members.

According to NSCP 2010Section 415, analysis of concrete footings included the

investigation of concrete footings under one-way and punching shear failure, and how the

reinforcing bars would be laid out in both directions of the footing. It has a provision on

the minimum thickness of footings and the location of the critical section for both one-

way and punching shear.


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Estimation and budget schedule are based on the technical data coming from a

professional Quantity Surveyor and/or Cost Engineer. The project schedule is prepared

and outlined using Microsoft Project containing all the significant and critical project

activities. Also included here are geotechnical profiles and field results of our project,

such as borehole results, soil consistence, cohesion and unit weight of the soil profile.

To facilitate the output of our project more accurately, the structural design

specifications shall be shown, like the beam, column, footing and slab schedule, at which

is presented the exact details like the number and size of top and bottom bars, the

concrete beam dimensions, and the effective depth of the structural members, per every

level and unit of our project. Preliminary data for design loads that served bases for our

structural design shall also be included, like the dead, live, superimposed, wind and other

essential loads of our project provided by NSCP 2010.


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5.1 Loads and Codes

5.1.1 Introduction

The structural design of the five-storey hospital structure conforms to the National

Structural Code of the Philippines 2010 for Volume 1: For Buildings and other Vertical

Structures and to the American Concrete Institute Code for Buildings. All values used in

the design are found in NSCP 2010: Minimum Design Loads. Seismic considerations are

in reference according to Uniform Building Code 1997.

5.1.2 Codes

SECTION 103: CLASSIFICATION OF STRUCTURE:

Nature of Occupancy: I Essential Facilities

Public School Buildings

SECTION 104: DESIGN REQUIREMENTS:

104.1 Strength Requirement: Strength capacity of the school building

104.2 Serviceability Requirement: Stiff and durable

104.3 Analysis: Load and resistance factor design

104.4 Foundation investigation

104.5 Design Review: Engr. Divina Gonzales

SECTION 105: POSTING AND INSTRUMENTATION

SECTION 106: SPECIFICATIONS, DRAWINGS, AND CALCULATIONS

SECTION 108: EXISTING STRUCTURES:


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5.1.3 Dead Loads

5.1.4Live Loads

First Floor Live Load Load Unit

Classrooms 1.9 kPa

Corridors above ground floor 4.8 kPa

Restrooms 2.4 kPa

Ground Floor corridors 4.8 kPa

Exit Facilities 4.8 kpa

Total 18.7 kPa

All Floors

Dead Load Load Unit

Ceiling:

Mechanical Duct Allowance 0.2 kPa

Plaster on Concrete 0.24 kPa

Elec. & Plumb Allowance 0.1 kPa

Acoustical Fiber Board 0.05 kPa

Floor Finishes

Cement Finish (25mm) 1.53 kPa

Ceramic or Quarry Tile (20mm) 1.10 kPa

Partitions:

Concrete Hollow Blocks 1 kPa

Total Dead Load 4.22 kPa


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Second Floor

Live Loads Loads Unit

Classrooms 1.9 kPa


Restrooms 2.4 kPa



Total 18.7 kPa

Third Floor

Live Loads Load Unit

Classrooms 1.9 kPa


Restrooms 2.4 kPa



Total 18.7 kPa

Fourth Floor


Classrooms 1.9 kPa


Restrooms 2.4 kPa



Total 18.7 kPa


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Fifth Floor

Live Loads Loads Unit

Classrooms 1.9 kPa


Restrooms 2.4 kPa



Total 18.7 kPa

Sixth Floor/ Roof Deck


Catwalk 1.9 kPa

Basic Floor Areas 1.9 kPa

Exit Facilities 4.8 kPa

Total 8.6 kPa

Total Live Load = 18.7 (First Floor)

+18.7(Second Floor)

Total Live Load = +18.7(Third Floor)

+18.7(Fourth Floor)

+30.7(Fifth Floor)

+8.6(Roofdeck)

Total Live Load = 114.1 kPa


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5.1.5Earthquake Loads

Design Considerations

Ct = 0.0731 (Concrete)

Overstrength Factor, R = 3.5 (ordinary concrete frame)

Soil Profile Type = SD

Zone no. = 4

Seismic Zone Factor, Z = 0.4

Ca = 0.44Na = 0.44

Cv = 0.64Nv = 0.768

Seismic Source Type = A

Na = 1.00

Nv = 1.2

Occupancy Category = I

Importance Factor I = 1.5 (Essential Facilities)

Valley Fault System

5.1.6 Wind Load

Design Considerations

The design shall conform to the NSCP Zone Classification Basic Wind Speed:

Manila Area (Zone 4):

V = 200 kph = 125 mph

Iw = 1.15

Exposure, B


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5.1.6 Load Combinations

U = 1.4D

U = 1.2D + 1.6L

U = 0.9D + 1.4E

U = 1.0D + 1.0W

U = 1.0D + 0.12E

Where:

D = dead load

L = live load

W = wind load

E = load effects of earthquake


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5.2 Structural Design

5.2.1 Introduction

Using application software such as STAAD and ETABS, the design of the

proposed school building will be utilized precisely and effectively. STAAD was used for

the two trusses that will cover the open spaced of the structure. ETABS designed the

whole super structure since the roof deck is made of reinforced concrete. Lastly, the

application software SAFE concentrated on the design of the foundation of the structure.

SAFE is an application that focuses on the design of the foundation; the data processed in

ETABS can be transferred through this program.

5.2.2 Beam Design

Using ETABS, the design and analysis of beams was computed.

***See Appendix

5.2.3 Column Design

Using ETABS, the design and analysis of columns was computed.

***See Appendix

5.2.4 Slab Design

Using ETABS, the design and analysis of slab was computed.

5.2.4.1 One Way Slab

***See Appendix


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5.2.4.2 Two Way Slab

***See Appendix

5.2.5 Design of Truss

The design of the truss in the structure to be considered is the open space found in

corridors of the school building. In order to prevent an overflow of water during typhoons

the materials used in the truss analysis are made of Howe Truss. The roof in the truss is

made of polycarbonate sheets.

5.2.5.1 Design Consideration

Polycarbonate Sheet (w = 4.0 kg/m2)

Polycarbonate Sheet Thickness, 4.5mm

Roof Live Load , RLL = 0.6 kPa

Dead Load ,DL = 0.096 kPa

Wind Load , WL = 0.6109 kPa

θ = 23.50°

f y = 170 MPa

Bay Distance , L = 3 m


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C 3 x 4.1

Orientation

Weight, w (kg/m) 6.14

Area, A (mm2) 781

Section Modulus about X,

Sx(x 103 mm

3)

18.14

Section Modulus about Y,

Sy(x 103 mm

3)

3.36

Reference : Association of Structural Engineers of the Philippines (ASEP)

Steel Manual

C 3 x 4.1:

Sx = 18.14 mm3

Sy = 3.36 mm3

W t = RLL + DL + WL

W t = 0.6 + 0.096 + 0.6109

W t = 1.3069 KPa

Load along x-axis:

Wx = Wt cos θ

Wx = 1.3069 cos 23.5

Wx = 1198.5189 N/m

Load along x-axis:

Wy = Wt sin θ

Wy = 1.3069 sin 23.5

Wy = 521.0952 N/m

WT

23.5o


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Actual stress along x-axis:

MPa

Actual stress along y-axis:

MPa

Allowable stress along x-axis:

MPa

Allowable stress along y-axis:

MP


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Checking for Adequacy:

Since 0.964 falls under 0.9 to 1.0, then the section of the purlins is adequate and

economical.

Top Chords, Bottom Chords and Web Members

The Section & Its Properties

Orientation

L 20 x 20 x 3

Weight, w (kg/m) 0.88

Area, A (mm ) 112

Radius of Gyration about X,

rx(mm) 5.9

Radius of Gyration about Y,

ry(mm) 5.9


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5.2.5.2 Design of Howe Truss

STAAD Model

3D Model


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STAAD Output

Table 5.3Support Reactions End Forces

JOINT LOAD FORCE-

X

FORCE-

Y

FORCE-

Z

MOM-X MOM-Y MOM Z

8 1 0.00 8 .99 0.00 0.00 0.00 0.00

2 0.00 0.00 0.00 0.00 0.00 0.00

12 1 -25.17 1.95 0.00 0.00 0.00 0.00

2 0.00 0.00 0.00 0.00 0.00 0.00

STAAD Output

Table 5.4 Member End Forces

MEMBER LOAD JT AXIAL SHEAR-

Y

SHEAR-

Z

TORSION MOM-

Y

MOM-

Z

1 1 1 -3.92 0.00 0.00 0.00 0.00 0.00

2 3.92 0.00 0.00 0.00 0.00 0.00

2 1 0.00 0.00 0.00 0.00 0.00 0.00

2 0.00 0.00 0.00 0.00 0.00 0.00

2 1 2 -1.47 0.00 0.00 0.00 0.00 0.00

3 1. 47 0.00 0.00 0.00 0.00 0.00

2 2 0.00 0.00 0.00 0.00 0.00 0.00

3 0.00 0.00 0.00 0.00 0.00 0.00


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3 1 3 -0.65 0.00 0.00 0.00 0.00 0.00

4 0.65 0.00 0.00 0.00 0.00 0.00

2 3 0.00 0.00 0.00 0.00 0.00 0.00

4 0.00 0.00 0.00 0.00 0.00 0.00

4 1 4 3.27 0.00 0.00 0.00 0.00 0.00

5 -3.27 0.00 0.00 0.00 0.00 0.00

2 4 0.00 0.00 0.00 0.00 0.00 0.00

5 0.00 0.00 0.00 0.00 0.00 0.00

5 1 5 3.43 0.00 0.00 0.00 0.00 0.00

6 -3.43 0.00 0.00 0.00 0.00 0.00

2 5 0.00 0.00 0.00 0.00 0.00 0.00

6 0.00 0.00 0.00 0.00 0.00 0.00

6 1 6 -3.92 0.00 0.00 0.00 0.00 0.00

7 3.92 0.00 0.00 0.00 0.00 0.00

2 6 0.00 0.00 0.00 0.00 0.00 0.00

7 0.00 0.00 0.00 0.00 0.00 0.00

7 1 7 0.00 0.00 0.00 0.00 0.00 0.00

8 0.00 0.00 0.00 0.00 0.00 0.00

2 7 0.00 0.00 0.00 0.00 0.00 0.00

8 0.00 0.00 0.00 0.00 0.00 0.00


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8 1 8 0.00 0.00 0.00 0.00 0.00 0.00

9 0.00 0.00 0.00 0.00 0.00 0.00

2 8 0.00 0.00 0.00 0.00 0.00 0.00

9 0.00 0.00 0.00 0.00 0.00 0.00

9 1 9 -10.34 0.00 0.00 0.00 0.00 0.00

10 10.34 0.00 0.00 0.00 0.00 0.00

2 9 0.00 0.00 0.00 0.00 0.00 0.00

10 0.00 0.00 0.00 0.00 0.00 0.00

10 1 10 -16.63 0.00 0.00 0.00 0.00 0.00

11 16.63 0.00 0.00 0.00 0.00 0.00

2 10 0.00 0.00 0.00 0.00 0.00 0.00

11 0.00 0.00 0.00 0.00 0.00 0.00

11 1 11 -17.98 0.00 0.00 0.00 0.00 0.00

12 17.98 0.00 0.00 0.00 0.00 0.00

2 11 0.00 0.00 0.00 0.00 0.00 0.00

12 0.00 0 00 0.00 0.00 0.00 0.00

12 1 12 7.19 0.00 0.00 0.00 0.00 0.00

1 -7.19 0.00 0.00 0.00 0.00 0.00

2 12 0.00 0.00 0.00 0.00 0.00 0.00

1 0.00 0.00 0.00 0.00 0.00 0.00


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13 1 2 1.95 0.00 0.00 0.00 0.00 0.00

12 -1.95 0.00 0.00 0.00 0.00 0.00

2 2 0.00 0.00 0.00 0.00 0.00 0.00

12 0.00 0.00 0.00 0.00 0.00 0.00

14 1 3 -0.59 0.00 0.00 0.00 0.00 0.00

11 0.59 0.00 0.00 0.00 0.00 0.00

2 3 0.00 0.00 0.00 0.00 0.00 0.00

11 0.00 0.00 0.00 0.00 0.00 0.00

15 1 4 0.52 0.00 0.00 0.00 0.00 0.00

10 -0.52 0.00 0.00 0.00 0.00 0.00

2 4 0.00 0.00 0.00 0.00 0.00 0.00

10 0.00 0.00 0.00 0.00 0.00 0.00

16 1 5 4 .49 0.00 0.00 0.00 0.00 0.00

9 -4.49 0.00 0.00 0.00 0.00 0.00

2 5 0.00 0.00 0.00 0.00 0.00 0.00

9 0.00 0.00 0.00 0.00 0.00 0.00

17 1 6 8 .99 0.00 0.00 0.00 0.00 0.00

a -8.99 0.00 0.00 0.00 0.00 0.00

2 6 0.00 0.00 0.00 0.00 0.00 0.00

a 0.00 0.00 0.00 0.00 0.00 0.00


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18 1 2 1. 47 0.00 0.00 0.00 0.00 0.00

11 -1.47 0.00 0.00 0.00 0.00 0.00

2 2 0.00 0.00 0.00 0.00 0.00 0.00

11 0.00 0.00 0.00 0.00 0.00 0.00

19 1 3 3.77 0.00 0.00 0.00 0.00 0.00

10 -3.77 0.00 0.00 0.00 0.00 0.00

2 3 0.00 0.00 0.00 0.00 0.00 0.00

10 0.00 0.00 0.00 0.00 0.00 0.00

20 1 5 -4.57 0.00 0.00 0.00 0.00 0.00

10 4 .57 0.00 0.00 0.00 0.00 0.00

2 5 0.00 0.00 0.00 0.00 0.00 0.00

10 0.00 0.00 0.00 0.00 0.00 0.00

21 1 6 -11.27 0.00 0.00 0.00 0.00 0.00

9 11.27 0.00 0.00 0.00 0.00 0.00

2 6 0.00 0.00 0.00 0.00 0.00 0.00

9 0.00 0.00 0.00 0.00 0.00 0.00


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5.2.6 Design of Foundation

It is essential to carry out investigation before preparing the design of civil

engineering works. The investigation may range in scope from simple examination of the

surface soils, with or without a few shallow trial pits, to a detailed study of the soil and

ground water conditions for a considerable depth below the ground surface by means of

boreholes and in-situ and/ or laboratory test on the soils encountered. The extent of the

investigation depends on the importance of the structure, the complexity of the soil

conditions, and the information already available on the behavior of the existing

foundations similar on soils. Thus, it is not the normal practice to sink boreholes and

carry out soil tests for single or two story structure since normally, there is adequate

knowledge of the safe bearing pressure of the soil in any particular locality. Only in

troublesome soils such as peat or loose fill would it be necessary to sink deep boreholes,

possibly supplemented by soil test. More extensive ground conditions where there is no

information available on foundation behavior of similar structures. Since the structure to

be design is school building, it is very important to consider the type of soil to design the

foundation efficiently and precisely. The type of soil to be design is the clayey soil

thereore we use “rat” or matt oundation

Information was extracted from site investigation to facilitate foundation design.

This includes

General topography of the site which affects foundation design and

construction e.g., surface configuration, adjacent property, presence of water

course, and so on.

Location of buried services such as power lines, telephone cables, water

mains, sewer pipes and so on.

General geology of the area within particular reference to the principalgeological formations underlying the site.

Previous history and use of the site including information of any defects and

failures of structure built on the site.


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Any special features such as possibility o0f earthquake, flooding, seasonal

swelling etc.

Availability and quality of local construction materials.

A detailed record of soil rock strata, ground water conditions within the zone

affected by foundation loading and of any deeper strata affecting the site

conditions in any way.

In designing the foundation of the structure, SAFE application was used. SAFE

application is software that focuses on foundation design. This software designs different

footings, from square footings, rectangular footings, combined footings, to matt footings

and other kinds of footings. In the design of footings Structural Analysis of Finite

Element was used. Matt Foundation is the type of foundation to be used in the design of

substructure of the proposed building. SAFE is the ultimate tool for designing concrete

floor and foundation systems. From framing layout all the way through to detail drawing

production, SAFE integrates every aspect of the engineering design process in one easy

and intuitive environment. It provides unmatched benefits to the engineer with its truly

unique combination of power, comprehensive capabilities, and ease-of-use. Laying out

models is quick and efficient with the sophisticated drawing tools, or use one of the

import options to bring in data from CAD, spreadsheet, or database programs. Slabs or

foundations can be of any shape, and can include edges shaped with circular and spline

curves. Post-tensioning may be included in both slabs and beams to balance a percentage

of the self-weight. Suspended slabs can include flat, two-way, waffle, and ribbed framing

systems. Models can have columns, braces, walls, and ramps connected from the floors

above and below. Walls can be modeled as either straight or curved.

We used raft foundation in designing soil foundation including different

parameters used in mat foundation design. Modulus of subgrade reaction, assumptions

and considerations to analyze mat as rigid or flexible foundation, loads that should

account in mat foundation design, thickness rigidity relationship of mat, and thickness

deflection relationship of mat was analyzed in the foundation design. In this post, we

learned about analysis model that are used in computer software SAFE.


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In this model finite elements are formed from object based model. Rectangular finite

element mesh is developed depending on maximum allowable element size.

Computer oriented method for structural analysis is used to solve plates (raft)

supported on elastic foundation. These rectangular finite elements are interconnected to

adjacent one only at corners (nodes) and a isolated spring that resembles to soil are used

in modeling.

Raft foundation is analyzed in SAFE based on classical theory for thick plates

supported on the winkler foundations. The isolated spring assumed in modeling soil is

called winkler foundation. This theory takes in to account the deformation due to

transverse shear of the plate. This model is shown in the figure below.

Mat foundations can include nonlinear uplift from the soil springs, and a

nonlinear cracked analysis is available for slabs. Generating pattern surface loads is

easily done by SAFE with an automated option. Design strips can be generated by SAFE

or drawn in a completely arbitrary manner by the user, with complete control provided

http://2.bp.blogspot.com/-nHl1NkMqfEA/UG5cpyMrhbI/AAAAAAAAFXg/wITV5p6pkWM/s1600/Structural+idealization+of+raft+and+supporting+soil.jpg


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for locating and sizing the calculated reinforcement. Finite element design without strips

is also available and useful for slabs with complex geometries.

Comprehensive and customizable reports are available for all analysis and design

results. Detailed plans, sections, elevations, schedules, and tables may be generated,

viewed, and printed from within SAFE or exported to CAD packages.

SAFE provides an immensely capable yet easy-to-use program for structural

designers, providing the only tool necessary for the modeling, analysis, design, and

detailing of concrete slab systems and foundations.


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5.2.6.1 Introduction

In designing the foundation of the structure, SAFE application was used. SAFE

application is software that focuses on foundation design. This software designs different

footings, from square footings, rectangular footings, combined footings, to matt footings

and other kinds of footings. In the design of footings Structural Analysis of Finite

Element was used. Matt Foundation is the type of foundation to be used in the design of

substructure of the proposed building.

From the recommended soil investigation, the presence of the very loose/soft

alluvial deposits between 0 to 9m depth would discourage the use of a shallow

foundation. This layer is settlement prone and/or highly compressible based on the SPT

blow counts. It is also strongly susceptible to liquefaction during a strong earthquake,

causing major damage to the structure under such an event. The soil bearing capacity is

estimated to be less than 25 kpa, considerably too low to support the structure without

shear failure and the settlement is extremely very excessive.

Higher bearing pressures of as high as 250 kPa can be generated below the bottom

level of the alluvium. However, this will require mat footings and a deep foundation

involving piles just to reach the hard strata wherein the stability of the foundation can be

assured.

Properties of Concrete to be considered in SAFE software:

Concrete Compressive Strength ’c Mpa

Modulus of Elasticity, E = 24650 Mpa


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Properties of rebars to be considered in SAFE software:

Weight Per unit Volume, 77 KN/m3

Modulus of Elasticity, E =200000 Mpa

Fy = 414 Mpa

Fu= 550 Mpa

Fig. 5.1 Shorter Direction Top Bar


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Fig. 5.2 Longer Direction Top Bar

Fig 5.3 Shorter Direction Bottom Bar


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Fig 5.4 Longer Direction Bottom Bar

Soil

Subgrade Modulus

Subgrade modulus of the soil from soft up to the hardest part which is bed

rock may vary from 100 to 500 lb/ in

3

.

From the soil investigation report, the subgrade modulus of the soil was

found to be clayey which makes the value up to 100 lb/ in3.

x

x

x

x

x

= 27000 KN/m3


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After run analysis ..

Fig. 5.5Longer Direction Bottom Bar Result

Fig 5.6 Longer Direction Bottom Bar Result


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Fig 5.7 Shorter Direction Top Rebar Result

Fig5.8 Shorter Direction Top Rebar Result


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5.2.7 Design of Concrete Mix

A concrete mix proportion requires an intelligent guess of optimum combination

based on previous experiences or relationships previously derived. The process to obtain

a satisfactory mix starts with:

Concrete mix proportioning must be executed properly. External factors, such as

moisture condition of aggregates, place where mixing is to be conducted; handling,

placing, transporting and weather conditions affect fresh and hardened properties of a

designed mix.

There are two applicable methods employed in designing the concrete

proportions, based on a Philippine setting. Under the ACI method, the absolute volume of

a concrete mix is taken to be one cubic unit of the material; thus, the sum of the

proportions of cement, water, air entrainments and aggregates must also be equal to 1

cubic unit by definition of concrete itself. On the other hand, the approximate sand-and-

water content method, a required submittal by the Department of Public Works and

Highways (DPWH), makes use of three basic specifications: a) the water-cement ratio is

taken to be 0.57, b) the fineness modulus (FM) of sand is 2.75, and c) slump of concrete

is 75 mm. In excess of these parameters, corrections among the proportions must be

applied in order to comply with these requirements. Compared to the absolute volume of

the concrete mix adopted in ACI method, it is taken as the reciprocal of the cement factor

(CF), which is expressed in the number of bags of cement needed to make per 1 cubic

unit of concrete. Similarly, the sum of the proportions of cement, water, air entrainments

and aggregates must also be equal to that amount.

It is to be noted that the proportions to be prepared under either of the two methods are

starting mixes only. In the course of mixing operations, the quality of concrete should be

Preliminary

ComputationsTrial Mix Checking Adjustments Trial Mix


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periodically checked for the following: workability, net water content and cement as per

yield test. Should it fail to meet the requirements according to the method employed,

adjustments shall be made to ensure the consistency of concrete throughout the structure.

The following presents the steps employed in designing a concrete mix:

Method 1 – The ACI Method

1) Given the design compressive strength o concrete, c’, identi the corresponding

water-cement ratio (Table E-3). Interpolation might be needed.

2)

Obtain the water requirement (Table E-4) taking the following parameters:

a) Type of Coarse aggregates (Angular/Rounded)

b) Maximum Aggregate Si