Effect of Heating on the Behaviour of Direct Shear Transfer in Self-Compacting Concrete

This laboratory research is concerned with the shear transfer behavior of self-compacted concrete SCC push-off specimens being exposed to high temperatures for one time or more. Two types of casting water are used, namely, tap water (drinkable) and raw water (undrinkable) which is brought from local wells, a situation which is currently under use in Iraq especially in large engineering facilities far from cities. Effect of heat exposure is also studied due to well-known unstable circumstances that Iraq faces. Twenty-four specimens are cast and some of them are exposed to different levels of heating. Later on after heating in an electrical furnace, specimens are cooled down by two ways, gradually, by leaving them to air for one day, and the fast way by gently putting in water. Testing of specimens is carried out by loading each one, using compression machine until failure. It is observed that using raw water in casting SCC (no heat exposure) leads to decrease in shear transfer strength and in vertical slip in addition to the decrement in compressive strength and tensile strength in comparison with using potable water. It is also observed that heating and then rapid cooling cause tangible shear transfer strength, slip, compressive strength and tensile strength decrease especially when raw water is used for concrete casting.