Temperature Dependence Tendency of the Strength Development of Ultra-Low-Shrinkage and High-Strength Zero-Cement Concrete

Abstract

Low-heat, ultralow-shrinkage, and high strength zero-cement concrete referred to as Sustain Crete-Zero (STC-Zero) has been developed [1,2,3,4,5]. While containing no cement, its binder comprises powders generally used for concrete: ground granulated blast-furnace slag, fly ash, silica fume, and an expansive additive. Thanks to its low-heat, ultralow-shrinkage, and high strength characteristics, STC-Zero drastically reduces the risk of cracking and enhances the durability of concrete structures. In other words, STC-Zero is a promising new construction material capable of reducing not only CO₂ emissions at early stages but also life cycle CO₂ (LCCO₂) including maintenance and renewal. This study focused on and experimentally examined the temperature dependence tendencies of the strength development of STC-Zero among its characteristics. To be specific, the strength of cores drilled from block specimens exposed outdoors and the indoor strength development under different temperature conditions were confirmed. As a result, it was found that (1) the strength gains of STC-Zero are greater at high temperatures and smaller at low temperatures than conventional concrete made using Portland cement; and (2) the strength development of STC-Zero cannot be uniformly evaluated by the generally adopted maturity factor based on equivalent age. The reason for this is discussed, focusing on the apparent activation energy at different equivalent ages.