Characteristics of Recycled Aggregate Concrete Produced with Crushed Stone Sand as Fine Aggregate

摘要

In this work the characteristics of recycled aggregate concrete produced with crushed stone sand as 100% replacement of desert stone were experimentally investigated. Concrete mixtures incorporating varying percent replacement of normal aggregate with recycled aggregate as coarse aggregate and crushed stone sand as fine aggregate were produced and tested at 7, 28, 56 and 90 days of concrete age for various hardened concrete properties. For one-on-one comparison, corresponding recycled aggregate concrete mixtures using desert sand as fine aggregate were also tested. Superior performance of crushed stone sand-based concrete mixtures was recorded for compressive and flexural strengths, static modulus of elasticity, abrasion resistance and water absorption characteristics when compared with that of the corresponding recycled aggregate concrete mixtures produced with desert sand as fine aggregate. No significant effect of crushed stone sand was recorded on the split tension strength of concrete mixtures. Improvement in mechanical properties and water absorption characteristics of crushed stone-based mixtures was, however, observed up to 50 wt.% replacement level of normal aggregate with recycled aggregate. Beyond this level of replacement, no noticeable difference in the performance of the two categories of recycled aggregate concrete mixtures was recorded. It is concluded that crushed stone sand can be effectively used as fine aggregate replacing desert sand to avoid the limitations caused in the mechanical properties of recycled aggregate concrete mixtures due to the use of desert sand as fine aggregate.