Abstract    The present paper reports the results of a series of experimental works designed to produce a Strong, Workable, Durable and Sustainable Concrete (water-cement ratio 0.4) in Subtropical Climate using Construction & Demolition waste (C&D waste) crushed bricks (12.04%, 16.05 and 20.07%) as replacement of natural sand (NS). The crushed bricks (CB) have been used earlier as a sand replacement, but in the present study it is also used as an Internal Curing (IC) agent. Most of the prominent studies on IC are based on European and American climatic standpoint whereas the present investigation is in the subtropical climate. To make up for the loss in strength due to the use of marginal material like CB as a sand replacement, additional low-lime class F flyash (5.26% and 11.11%) is used. The combined effects of the two adjustments have resulted in improvement in workability, reduction in shrinkage, increase in strength, improved microstructure and Interfacial Transition Zone (ITZ) of concrete. To improve the flexural strength glass fiber (0.2%) is used effectively. The SEM images also validate the improvement in the microstructure and ITZ.

Keywords    Construction & Demolition (C&D) Waste, Concrete, Internal Curing (IC), Interfacial Transition Zone (ITZ), Shrinkage, Sustainability.

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