Bond behavior of reinforcement in Lightweight Aggregate Self-Compacting Concrete

• Pumice sand replacement with normal-weight one considerably increases bond strength.
• All-LWASCC bond strength (splitting) is by approx. 80% lower than that of NWSCC.
• All-LWASCC bond strength (pull-out) is by max. 30% lower than that of NWSCC.
• Bond length increase leads to decreasing of the max. normalized bond stress, τu∗.
• Increase of bar dia. increases/decreases τu∗ for pull-out/beam tests, respectively.

An investigation of the steel-to-concrete bond in Lightweight Aggregate Self-Compacting Concrete (LWASCC, comprising exclusively pumice aggregates) is presented based on direct pull-out and beam tests. Experimental parameters include: rebar diameter, bond length and type of additive used in the LWASCC mixture. The results are compared with those obtained from identical specimens made of: (i) pumice aggregate self-compacting concrete (PASCC) with normal-weight sand and (ii) normal-weight SCC (NWSCC). The majority of specimens exhibited failures due to splitting (at relatively low slips) and rebar pull-out for direct pull-out and beam tests, respectively. Empirical formulations are used to predict experimentally derived bond strengths.