膨胀剂对孔道压浆料限制膨胀率的影响

Effect of expansive agent on the restrained expansion rate of duct grouting material

研究了C4A3S-CaO双膨胀源体系和MgO单膨胀源体系下,预应力孔道压浆料在水养条件下限制膨胀率的变化趋势。结果表明:随膨胀剂掺量的增加,压浆料限制膨胀率逐渐增大。在合理掺量下,C4A3S-CaO双膨胀源体系对压浆料早期限制膨胀率的提升作用较明显,而MgO单膨胀源体系对压浆料后期体积稳定性的保持更优异。2种膨胀剂对于压浆料早期抗折和抗压强度的影响不大,其中,双膨胀源体系下的压浆料在膨胀剂掺量为8%时,抗压强度较空白组有小幅度的提高。

The variation trend of the restrained expansion rate of pre-stressed duct grouting material in water was studied under calcium sulphoaluminate hydrate-calcium hydroxide(C4A3S-CaO) dual-expansion system and magnesium oxide single-expansion system. The results show that the restrained expansion rate of grouting material gradually increases with the increase of expansive agent. Under the reasonable dosage,C4A3S-CaO dual-expansion system is more effective in improving early restrained expansion of duct grouting material. But magnesium oxide single-expansion system maintains better volume stability during later period. Two expansion agents have little effect on the early flexural and compressive strength. When the amount of expansive agent with two expansive sources was 8%,the compressive strength increased in a small range compared with blank group.