placing, finishing, curing and jointing concrete pavement finishing curing... · placing,...

Placing, finishing, curing

and jointing concrete

pavement

ASCP Forum 14 March 2016 Todd Myers Director/Owner TSM Civil Project Management

President ASCP

TOPICS

1. Placing

2. Finishing

3. Curing

4. Jointing

PLACING, FINISHING, CURING &

JOINTING CONCRETE PAVEMENTS

ASCP Forum 14 March 2016

1. PLACING – Mixing & Hauling


Local premix concrete supplier (Dry mix)

Delivery in agitators

1. PLACING – Fixed Form


Fixed form paving

placing options

1. PLACING – Slip form


Concrete Dumped on Grade



Restricted Access – Material Transfer Placer



Dowels/cages – Placer Spreader

1. PLACING – Where to Place?


Minimise the auger/plow work. It is a paver, not a dozer

As close as possible

to its final location

For both:- slipform

- fixed-form

to minimise handling

1. PLACING – Start of day - Caution


Start Day ‘Transition Pour’ Length TBA

Direction of paving

1. PLACING – End of day - Caution


Need to cut back

into good concrete

Hand vibration of

‘Transition Lot’ in timely

manner at Start & End of

day


2. FINISHING

Finishing: Is the process where surface marks or small localised high spots are

corrected.

This is separate activity to compaction.


2. FINISHING

Helicopter floats

not suited to

pavements

They do not give

the right type of

surface texture

AND Curing

should have

started long ago.


2. FINISHING – Tools & equipment

Bull float

Hand floats Wood & Steel

Scraping Straight Edge

Edging tools are not normally used at joints or edges for highway pavements

But these may be applicable for footpaths/cycle ways!



Bull float

Short, light flat

blade, hinged for even contact

‘Float’ only

limited to closing surface marks only


Hand Float

Use limited to minor

‘touch up’ only near

edges

basic rules :

1. Do not hand float if

not necessary

2. Use to the absolute

minimum required

If excessive required

need fix paving process


Scraping Straight Edge

Length & weight allow

‘scrapping and filling of

pop marks or slight high

spots

About 2m (+) long

Steel angle or hollow

section, long handle

Caution - In hands of

inexperienced may

create issues


2. FINISHING – Bleeding

Use either a bull

float or hand float in

a way that works

the surface bleed

water back into the

surface!!



3. Finishing - Texturing

Texturing is process of producing a skid

resistance surface - Micro texture

RMS R83 Up to 80 km/h

Hessian drag (or broom)

(min 38% sand in aggregate)

Over 80 km/h (and Roundabouts)

Hessian drag (longitudinal)

+ Tyning (transverse or longitudinal)


3. Finishing - Texturing

Produced by;

• Hessian Drag

• Broom finish


3. Finishing – Texturing hessian

KEY points for good hessian drag texturing

Attach to work bridge or platform behind paver at right angles to paving

Double layer in contact with concrete

Minimum 0.5 m (could be =1.5m) in contact with concrete.

Avoid bunching at edges

Watch for buildup of wet or dry mortar (warm weather)

Dampen at start & Renew drag each paving day


3. Finishing – Texturing broom

Suggested points for good broom finish

Light broom, not heavy ‘bass’ broom.

Use only dead weight of broom – don’t lean on it,

don’t ‘gouge’ surface

Straight slightly overlapping runs at right angles to

pavement

Clean broom after each pass – knock dags out,

barrow with water and shake mortar out


3. Finishing – Tyning Hand Pours

Finished product

The tynes are long to allow

‘flat curved’ contact with

concrete


4. CURING

What is curing?

CURING is a process of retaining moisture at a

reasonable temperature to keep the reaction between

cement and moisture going. In the first day or so if either; • Concrete completely dries out, or

• Concrete freezes The reaction stops but CANNOT be restarted !!!


4. CURING

Curing is important for;

Strength – pavement life &

Durability - surface wear resistance


4. CURING

Curing – Ideal conditions

Concrete laboratory.

This is perfect,

under water &

controlled

temperature

Not practical in field


4. CURING

Two main RMS requirements for

curing membrane

a continuous unbroken film (no gaps or holes when

applied)

maintained intact for 7 days (any damage made good ) or

concrete 25 Mpa


4. CURING

Effectiveness of curing compounds

Wax or

hydrocarbon OK

Acrylics -

check test

certificates

carefully !


4. JOINTING

“People Breathe - Concrete Cracks”**

All we can do is control where it cracks

**Dr Manton Hall UNSW (Concrete Technology 101 – 1986)


4. JOINTING

Typ Joints

Along – 4.2m

Across – 4.3m

Essentially

square slabs


4. JOINTING

Typically sawing 4- 8 hours after pour, depend on; • Air temp. • Conc. Temp • Wind • Season • Sun/Shade • Etc, Etc


4. JOINTING

Typical Saw cut width 6-7mm Crack will form 1-5 days Cleaning is very important No sealing > 7 days Joints must be dry Common Silicone Sealants

• Dow Corning 888 • Parchem Road Seal SL


PLACING, FINISHING, CURING &

JOINTING CONCRETE PAVEMENTS

Thankyou

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