有机硅提升磷石膏矿渣砖耐水性能研究OA

The large-scale stockpiling of phosphogypsum(PG),an industrial solid waste,causes environmental problems,and its subpar mechanical properties and poor water resistance restrict its resource utilization.To achieve high-value utilization of PG,PG and slag were used as the main raw materials to make PG-slag paving bricks.Silicate cement(OPC)and sulphaluminate cement(SAC)were respectively combined with steel slag and calcium hydroxide(as alkaline activators)to improve mechanical properties,while organosilicon water-repellent was added to enhance water resistance,thus preparing non-baked PG-slag paving bricks.Experimental methods included water absorption,softening coefficient,freeze-thaw cycle and anti-slip performance tests.Results showed that cement type had a significant impact on water resistance:only groups O-1 and O-2 in the OPC system met national standards,while all groups in the SAC system met the requirements.The optimal dosage of organosilicon water-repellent was 1%,and the S-1-1 group had the best water resistance with 0%water absorption and 1.55 softening coefficient.In the freeze-thaw and anti-slip tests,groups S-1 to S-3 and O-2 met the D25 grade and anti-slip requirements.The S-2-1 group had the best anti-slip performance with a BPN value of 74,and the S-1-1 group had the best frost resistance with a strength loss rate of only 3%.