COMPRESSIVE AND TENSILE STRENGTH OF CONCRETE MADE WITH RECYCLED AGGREGATES, MARBLE DUST, AND BAMBOO FIBERS
Keywords:
Green concrete, demolished waste, marble dust, bamboo fiber, recycled coarse aggregates, cement replacement, fibrous concrete, compressive strength, tensile strengthAbstract
The effect of recycled coarse aggregates, marble dust and bamboo fiber on compressive and tensile strength of concrete is presented in this article. Recycled aggregates were developed from demolished waste, marble dust was produced from marble slug of marble cutting shops and bamboo fiber was developed from bamboo root. The concrete mixes were designed using 1:2:4 mix ratio and 0.5 water cement ratio. For checking the results of proposed concrete mixes, a batch was developed only with conventional and recycled aggregates. First the dosage of marble dust was optimized using marble dust from 2.5% to 15% (2.5% increment). Thereafter, the optimized dosage of the marble dust was kept constant and dosage of bamboo fibers was varied from 1% - 1.5% (0.1% increment). In all proposed mixes 50% recycled aggregates were used. In each batch six cylinders of standard size were prepared for compressive and tensile strength testing. Curing of all specimens was done for 28-days. Load recorded from compression testing was recorded and converted in compressive strength of concrete containing marble dust. The results revealed 12.5% dosage as optimum with 41% and 50% increase in compressive and tensile strength respectively. The second group of specimens containing optimized dosage of marble dust and varying percentage of bamboo fibers were tested for compressive strength in similar fashion. The results showed 1.2% of bamboo fibers as optimum with 51% higher values than control concrete and 7% higher than recycled aggregate concrete containing optimized dosage of marble dust only. Analogous to compressive strength, split tensile strength of all specimens in both groups was tested. The highest results of the parameter were observed at same optimized dosage of marble dust and bamboo fibers. This shows that the combined effect of three additives on strength properties of concrete is positive. Hence can be used in structural concrete with due care of water cement ratio.
