Evaluation of Concrete Cores from On-going Construction Site in Kuwait

Short write up:

Concrete used for the construction of a residential building in Kuwait had durability problems, particularly, recuring low compressive strength of the concrete.

Using petrographic Analysis (ASTM C856) we found the major cause of the low compressive strength of the two cored samples is the overall high water content used for the concrete. The samples showed sufficient evidence that the concrete was also re-tempered. Re-tempering is the addition of water to a hardening concrete and re-mixing it for a period to render it easy to pour and place.

Residential Building 1

Residential building under construction

2 1

Two samples received for testing

3

Petrographic photo showing a cracked aggregate de-bonded from cement paste.

4

Petrographic photo showing high water content in concrete