ABSTRACT
In Brazil, one of the most used aggregates in the concrete blocks production is gneiss. There is few information in literature about the behavior of concrete blocks with this type of aggregate at high temperatures. Besides that, the test procedures to determine the concrete stress-strain curve is generally prescribed for cylindrical cast specimens. The concrete’s properties in this type samples are different from those produced in concrete block industries that use large vibrating presses with strong compaction energy and low cement consumption. This paper describes the effects of temperature on the mechanical properties of concrete blocks made with gneiss aggregate. For this, the CMUs were heated to 800°C and their residual compression strength and deformability was determined. The test method was adapted from the RILEM TC 200-HTC recommendations. In conclusion, the aggregate was thermally stable, and the residual compressive strength of the concrete block was basically unchanged below 400°C.
