Rubber concrete compressive strength testing

Presence of rubber also makes concrete more ductile or giving . Figure 11.2 shows the force-time response (displacement control) for two compressive strength tests in which... 

The ultimate compressive strength of the RubCon samples is 94.8 MPa. It is shown in Figure 1.9 that the strength of the concrete samples decreases moderately regardless of the environment s humidity. After a 50-day exposure, the strength limit stabilizes and remains unchanged until the end of the test. This can be explained by low water absorption of the rubber polymer concrete, not exceeding 0.05%. 

Figure 11.2 Force-time response for the compression of two concrete cylinders. The cylinder without rubber has a higher compressive strength but lower failure strain and energy absorption. The cylinder with rubber shows an opposite trend. Such a trend has been extensively observed in other similar tests [11].

At the low level of rubber, rubber concrete essentially functions like controlled concrete and it appears that one possible application is as a replacement for air entrained concrete. The results obtained from the test site in NAU indicate that, while it performs well in a cold climate, rubber concrete has the advantage of higher compressive strength than air entrained concrete. Also, while it has good ability to resist cracks, rubber concrete may be used as controlled concrete but with fewer or no expansion joints. 

El-Gammal and co-workers [49] investigated the density and compressive strength of concrete that contained waste tyre rubber at various levels. The waste rubber had been used to replace equivalent amounts of fine and coarse aggregate in the test mixes. The results showed that, although there was a significant reduction in the compressive strength of the rubber modified concrete, the products demonstrated a ductile, plastic mode of failure as opposed to the brittle failure common with standard concrete. 

---