SAP掺量对UHPC性能的影响及机理研究

Study on the Influence and Mechanism of SAP Content on UHPC Performance

针对UHPC收缩大、抗裂性差等问题,将经预湿水处理的高吸水性树脂SAP掺入UHPC中,对比研究了SAP掺量对UHPC性能的影响,并分析其作用机理。结果表明:SAP能有效缓解UHPC的扩展度经时损失;随着SAP掺量的增加,UHPC的扩展度逐渐增加,而抗压强度逐渐降低,且SAP对UHPC早期抗压强度的影响更大;SAP可改善UHPC的自收缩,且掺量越大,改善效果越明显;掺量为0.1%、0.2%的SAP均能改善UHPC的抗氯离子渗透性能,但当掺量超过0.2%时,SAP会降低UHPC的抗氯离子渗透性能和抗冻性能。

Aiming at the problems of large shrinkage and poor crack resistance of UHPC,the influence of super absorbent polymer SAP dosage on the performance of UHPC with the SAP treated with pre-wet water was studied,and its mechanism was analyzed.The results show that SAP can effectively alleviate expansion loss over time of UHPC with the increase of SAP dosage,the expansion degree of UHPC gradually increases and the compressive strength gradually decreases,and SAP has a greater influence on the early compressive strength of UHPC.SAP can improve the self-shrinkage of UHPC,the greater the dosage,the more obvious the effect.The dosage of SAP with 0.1%and 0.2%can improve the chloride ion erosion resistance of UHPC,but when the SAP dosage is more than 0.2%,it can lead to the reduction of the chloride ion erosion resistance and the frost resistance of UHPC.