Enhance concrete performance using natural materials as partial replacement of cement

الملخص EN

In the last decades, the use of residue in civil construction, especially in addition to concrete has been studied by many researches related to, besides to reduce the environmental polluter’s factors.

This may lead several improvements of the concrete properties.

In recent years increasing attention towards utilizing less energy intensive materials, such as fly ash, rice husk ash, condensed silica fume and slag, in combination with cement to achieve energy saving.

This research evaluates how adding rice husk ash (RHA) to concrete may influence its physical and mechanical properties.

RHA of 8 % and 10 % were replaced partially as cement.

Also, the research studies the effect of adding Iraqi slag (SS) (steel slag) as partial replacement of cement.

Slag is a by-product from pig-iron production process, which causes environmental problem remains as disposals when not used.

In this research cubic samples of (100x100x100) mm were tested to evaluate compressive strength, cylindrical samples of (100 diameter x200 high) mm were used for testing splitting tensile strength, and prism samples of (100x100x400) mm were tested for flexural strength.

All samples were tested after 28 days curing.

Three mixes were prepared, the first mix with partial replacement (8 %, 10 %) of RHA as cement which gave enhancement in compressive strength of 46MPa while it was 33 MPa for ordinary concrete and 22 MPa for slag concrete ,the second mix with partial replacement (40 %) of SS) of cement SS gave enhancement in splitting tensile strength by 4.7 MPa while it was 2.6 MPa for ordinary concrete mix and 5 MPa for RHA mix and the third was plain concrete (to compare with) without replacement all tests were made after 28 days of curing.