March 6-8, 2014

ABSTRACTS OF PAPERS PRESENTED BY DLSU CE FACULTY AND STUDENTS

An Artificial Neural Network Approach to

Structural Cost Estimation of Building Projects in the Philippines

Roxas, Cheryl Lyne C. and Ongpeng, Jason Maximino

Abstract: The objective of this study is to develop an artificial neural network (ANN) model that can predict the total structural cost of building projects in the Philippines. Data from thirty building projects were collected and randomly divided into threesets: 60% for training, 20% for validating the performance and 20% as a completely independent test of network generalization. Six input parameters, namely: number of storeys, number of basements, floor area, volume of concrete, area of formworks, and weight of reinforcing steel. These variables were entered into the ANN architecture and simulated in MATLAB. The feedforward b ackpropagation technique was used to generate the best model for the total structural cost. The best ANN architecture consists of six input variables, seven nodes in the hidden layer and one output node. The resulting ANN model also reasonably predicted the total structural cost of building projects with favourable training and testing phase outcomes.

Parallel Session on Sustainability, Environment & Energy

A Study on the Applicability of Replacing GI Wires with Plastic Cablein Structural MembersNevin Y. Balibrea, Louie Mart M. Montrias, Gregorio S. Uymatiao III Kelvin Gerard N. Yao and Dr. Bernardo A. Lejano

Abstract: This study aims to investigate the possibility of replacing GI wire with commercial plastic cable ties and evaluate its effect on the structural integrity of a reinforced concrete member. The two major factors that shall be focused in this study is the overall strength of the structural member and the time consumed to tie steel bars using both tie materials. A reinforced concrete column was also tested based on the Standard Compression Test (ASTM C39) to assess the effect of using plastic cable as tie wire. From these tests, the researchers determined that although the strength of the plastic cable is slightly weaker than that of the GI wire in the modified pull-out test, the resulting strength from the compression test of the reinforced concrete column samples is still higher than the requirement stipulated in the 2010 NSCP. As for the tying speed of an amateur worker, thetime used for tying with plastic cable is almost one-third only of that of the GI wire.

Parallel Session on Sustainability, Environment & Energy

Investigation of the Strength of Cold-Formed Steel C-Section in Compression

Arvin Patrick Yu and Dr. Bernardo A. Lejano

Abstract: The objective of this study is to verify experimentally and computationally the performance of C-shaped Cold-Formed Steel (CFS) when subjected to concentric axial compression load considering buckling. The experimental aspect subjects the CFS members with compressive loads using hydraulic jacks and load cell. For the computational aspect, provisions found in the NSCP were used to determine the strength in compression of the members based on the actual dimensions, thicknesses and lengths of the member together with the material properties of the steel. This was done to a total of 126 samples with 1 section shape, 6 different lengths and 5 different thicknesses. It was found that the strength calculations for both distortional buckling failure and torsional-flexuralbuckling failure given by the NSCP provisions were not consistent with the results of the compression tests. For shorter lengths, distortional buckling prevailed as the main failure while for longer lengths, torsional-flexural buckling occurred. All of the predicted strength were highly conservative and well below the experimental value.

Parallel Session on Sustainability, Environment & Energy

Application of Response Surface Methodology:Optimum Mix Design of Concrete with Slag as Coarse Aggregate

Rhea Regulacion and Dr. Andres Winston Oreta

Abstract: To determine the mix design that will yield the optimum compressive concrete strength, response surface methodology (RSM) is explored in this study. RSM is an optimization tool that interprets experimental results even in a non-linear response surface manner. RSM was used on the data obtained from laboratory experiments conducted by the researchers. The experiments conducted include the influencing factors: slag percentage (50%, 75%, and 100%), curing period (14 days, 21 days, and 28 days), and types of cement (1P, I, and IP), and the interaction effects of these factors in compressive strength test are analyzed in this paper through response surface methodology. The responses of each specimen have showed significant increase in attained strength with respect to the control specimens.

Parallel Session on Sustainability, Environment & Energy

Outcomes-Based Assessment of a Basic Engineering Course (Statics of Rigid Bodies)

Dr. Andres Winston C. Oreta and Cheryl Lyne C. Roxas

Abstract: This paper presents the implementation of the Outcomes-Based Education (OBE) framework in a basic undergraduate engineering course – Engineering Mechanics (Statics of Rigid Bodies), from syllabus design to course assessment. The revision of the syllabus using the OBE format was carried-out and outcomes-based assessment is conducted to determine if the intended learning outcomes for this course using the revised syllabus are achieved. Two types of assessment methods were applied: direct and indirect methods to assess the attainment of the course learning outcomes. The direct method used the scores in the quizzes and final exams. The indirect method using an end-of-course evaluation by the faculty and students to determine the perception on the achievement of outcomes. Based on the outcomes-based assessment using direct methods, the achievement of the learning outcomes is barely satisfactory and a review of the course syllabus and teaching and learning activities is recommended.

Symposium on Scholarship & Innovation in Teaching & Learning (SILT)

Mode Choice and Value of Time of Inter-Island Travellers: The Case of the Philippines

Krister Ian Daniel Z. Roquel and Dr. Alexis M. Fillone

Abstract: This study covers the development of logit choice models, based on revealed preferences of the traveling population across the Panay-Negros islands. It was found that the travel mode characteristics like travel time, cost, comfort as well socio-demographic information like age and income, were significant in travel decision. The average value of travel time savings was computed to be at Php 87.89 / hour ($ 2.04 / hour). Furthermore, estimated value of time of different groups based on travel frequency, day of travel, gender, civil status, income class, and trip purpose were also determined. These values can be used in feasibility analysis of various transport infrastructures that may be introduced to the network.

Graduate Students Colloquia