Development and Investigation of a New Low-Cement-Consumption Concrete—Preplaced Aggregate Concrete

Reducing consumption of cement in concrete will achieve huge benefits in decline of carbon emission, conservation of natural resources and reduction of the cost of concrete. In this paper, the low-cement-consumption concrete, preplaced aggregate concrete (PAC), is prepared and 12 types of mixtures including four water–binder ratios (W/B) and three sand–binder ratios (S/B) are designed to detect the effect of W/B and S/B on the mechanical properties and failure mechanism of PAC. Experimental and analytic results indicate that the cubic compressive strength of PAC, splitting tensile strength of PAC and elastic modulus of PAC decrease with increase in W/B and S/B. At a similar compressive strength, more than 20% increment of elastic modulus of PAC is achieved when compared with normal concrete (NC); the descent stage of stress–strain curves of PAC are steeper than that of NC and the peak strains of PAC is lower than that of NC. Guo’s model with suitable values of parameters a and b can be used to describe the stress–strain relationship of PAC. Replacing NC by PAC in concrete structures will save 15–20% cement and achieve great environmental and economic benefits.