Performance of low-embodied CO2 and high early-age strength concrete full-sized slabs

High early strength and low-embodied CO2 concretes were analyzed in full-sized slabs under California weather. Belitic calcium sulfoaluminate (BCSA), ordinary portland cement (OPC), portland limestone cement (PLC), and calcined clay (CC) were the used cementitious materials. Each material was designed to obtain a flexural strength of 2.76 MPa (400 psi) at opening time, which varied depending on the material between 4 and 10 hours. One individual slab of 4.5 x 3.6 m (15 x 12 ft) with a thickness of 23.5 cm (9.25 in) was analyzed for each material. Thermocouples and vibrating-wire strain gages (VWSG) were installed at the corner and center of the slab to monitor the slab behavior through time. The VWSGs were placed at two depths to track the differences in strains at the top and bottom of the concrete slab. Testing performed in the slabs and laboratory-prepared specimens included: corrosion, carbonation, alkali-silica reaction (ASR), albedo, flexural strength, compressive strength, and shrinkage. Low-embodied CO2 concretes with high early strength are a sustainable paving alternative concrete based on reduced carbon emissions and carbon intensities when compared to traditional concrete structures. By providing performance improvements such as higher strengths and lower shrinkage, these alternative new materials for construction and repairs will enable construction windows to be reduced, which will benefit the user and the owners. Life cycle analysis (LCA) and mechanical properties were used to determine that low-embodied CO2 concrete providing high early strengths are sustainable alternatives that can be used instead of traditional methods.