ABSTRACT:
In this paper report we have discussed about the use of recycled concrete aggregate in the concrete and the effects on its compressive strength by progressively replacing the natural concrete aggregate (NCA) by recycled aggregate. It is the experimental study of recycled concrete aggregate (RCA) when it is compared with the natural concrete aggregate on account of its properties.
Cubes having dimension 150x150x150 mm3 were casted using recycled aggregate by replacing the natural aggregate by 0%, 25%, 50% and 75% and corresponding results of compressive strengths were noted. The 28 days compressive strength was noted by crushing the cube at 7, 14 and 28 days and it was found that performance of concretes with 0% and 25% replacement
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In this paper we have studied compressive strength of concrete by replacing natural aggregate with recycled aggregate by 25%, 50% and 75%.This mixture formed in the sample of cubes of dimension 150x150x150mm3.
The proportion of different constituents in mixture is as follows:
Notation RCA%
Constituents Kg/m3 RCA (kg) NCA(kg) Fine Agg. (Sand) Water (litre) Cement
M20 0% 0 64.68 29.71 9.74 20
M20 25% 16.17 48.51 29.71 9.74 20
M20 50% 32.34 32.34 29.71 9.74 20
M20 75% 48.51 16.17 29.71 9.74 20
The load test on cubes was performed on 7th days, 14th days and 28th days. The load to be applied by UTM machine to the opposite side of the cube and cast placed centrally between the plates. The load to be applied without shock increased continuously at the rate of approximately 140 kg/cm2/min. when the maximum load was applied cube got cracked in inclined direction.
The result of the load test was as below:
Mix RCA % 7 Days 14 Days 21 Days
M20 0% 1.60 1.72 20.6
M20 25% 1.58 1.67
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