An assessment of the risk of thermal cracking in self-compacted lightweight mass concrete

The use of Self-Compacted Lightweight Concrete (SCLC) in massive structures such as bridges can help solve the challenges of these structures, including a high amount of dead load, congested reinforcement and early-age cracking. In this paper, 12 concrete mixes comprising eight SCLCs with Scoria and Leca aggregates and four Self-Compacted Concretes (SCC) were produced. Two water-to-binder ratios (0.35 and 0.4) and coarse percentages (30% and 40%) were considered. The thermal conditions of the core of massive structures were applied to specimens via Thermal Match Curing System (TMCS). Compressive and tensile strength, modulus of elasticity, density, water absorption and coefficient of thermal expansion were measured experimentally in three curing regimes (water, lab and TMCS). The results indicated that it is possible to produce self-compacted lightweight concretes with proper workability and mechanical strength. Specimens that experienced thermal curing to represent the core of mass concrete showed improved mechanical properties. Temperature regime and risk of thermal cracking were measured for concretes. SCLCs had a lower risk of thermal cracking compared to SCC ones, though they had higher temperature deference. This can be attributed to the lower coefficient of thermal expansion and modulus of elasticity in SCLCs.