纳米SiO_(2)和CaCO_(3)对超高性能混凝土性能的影响

INFLUENCE OF NANO SIO_(2)AND CACO_(3)ON THE PERFORMANCE OF ULTRA HIGH PERFORMANCE CONCRETE

制备超高性能混凝土(简称UHPC)时掺入纳米材料能够明显提高其强度,通过试验对比分析了标准养护和热水养护条件下纳米SiO_(2)和纳米CaCO_(3)对UHPC性能的影响,结果表明:同种养护方式,不同掺量下,两种纳米材料均会不同程度上降低UHPC的流动度,但纳米CaCO_(3)对UHPC流动度的降低程度较小。相同掺量下,热水养护的效果优于标准养护。热水养护时,纳米SiO_(2)在掺量为2%时,对UHPC的抗压强度和抗折强度提升效果最好,抗压强度最高可达143.8 MPa,提升了13%;纳米CaCO_(3)在掺量为3%时,对UHPC的抗压强度和抗折强度提升效果最优,抗压强度最高可达到138.3 MPa,提高了9%。

The strength of ultra-high performance concrete(UHPC)can be significantly improved by adding nano-materials.The effects of nano-SiO_(2)and nano-CaCO_(3)on the properties of UHPC under standard curing and hot water curing conditions were compared and analyzed.The results show that under the same curing method and different dosage,the two kinds of nano-materials will reduce the fluidity of UHPC to varying degrees,but nano-CaCO_(3)has little effect on the fluidity of UHPC.When the content of nano-SiO_(2)is 2%,the compressive strength and flexural strength of UHPC are the best,and the compressive strength is up to 143.8 MPa,which is increased by 13%.When the content of nano-CaCO_(3)is 3%,the compressive strength and flexural strength of UHPC are the best,and the compressive strength can reach 138.3 MPa,which is increased by 9%.