Study on the effect of low temperature and low humidity curing conditions on the properties of early age self-compacting concrete

Different curing conditions of temperature and humidity will change the mechanical properties of early-age selfcompacting concrete. In order to evaluate the effect of low temperature and humidity on self-compacting concrete, uniaxial compression test and splitting tensile test were carried out on the early-age self-compacting concrete under different curing conditions (20℃-95%RH, 10℃-75%RH, 3℃-50%RH) to study the evolution law of mechanical properties of early-age self-compacting concrete under non-standard curing conditions and analyze the change rule of porosity with age in combination with NMR(Nuclear Magnetic Resonance). The mechanical properties of early-age self-compacting concrete were studied under non-standard curing, and the variation rule of porosity with age was analyzed by combining with nuclear magnetic resonance (NMR) technology. The experimental results show that, with the growth of age, the compressive strength and split tensile strength of SCC increased from 2.76 MPa, 7.23 MPa and 7.81 MPa at 3 days age to 14.5 MPa, 17.3 MPa and 22.9 MPa at 28 days age under the three curing conditions of 3℃-50%RH, 10℃-75%RH and 20℃-95%RH, and porosity decreased from 18.6%, 17.65%, and 16.44% at 3-day age to 14.56%, 12.69%, and 10.99% at 28 day age, respectively.