GOOD CONCRETE PRACTICES – TIPS

GOOD CONCRETE PRACTICES – TIPS 

Concrete is a mixture of cement , sand , aggregates , water and admixtures  For making good concrete certain practices needs to be followed .
Those practices can be summarised as follows:

1. Quality of incoming materials : 

Check the following : 
a. Cement Test certificate  : Parameters of cement like compressive strength , setting time , fineness etc
b. Sand : Silt content & Sieve analysis
c. Coarse aggregates : Sieve Analysis
d. Chemical Admixtures : Solid content ; Base of the admixture – whther naphthalene, melaimine or PC based

2. Availability of Mixers 
It is advisable to do mixing using concrete mixers.  Hand mixing will produce non uniformity in quality of concrete

3. Transportation of concrete 
It is advisable to use concrete as quickly as possible . A delay in using concrete can lead to quality issues .
Therefore plan for transportation of concrete in the quickest possible time using wheelbarrows, transit mixers etc

4. Use cover blocks for concrete structures for durability

5. Check the slump of concrete using a slump cone

6. Avoid using excess water in the concrete mix. Excess Water could lead to lower compressive strength and increase in cracks

7. Use vibrators for better compaction of concrete : Use needle vibrators for better compaction and to remove air voids

8. Make available the finishing equipments for better finish
9. Curing should be done for a minimum of 10 days for enabling the concrete to achieve high compressive strength and durability

10. Formwork / shutters should not be removed very quickly : Vertical formwork to columns can be removed within 16-24 hours; Props to slabs spanning  upto 4.5 m should be removed within 7 days , beyond 4.5 m props to be removed within 14 days ; Props to beams and arches for span upto 6 m can be removed within 14 days , props spanning over 6 m can be removed within 21 day