不同产地机制砂对UHPC性能的影响

Influence of manufactured sands from different regions on UHPC performance

对比了甘肃本地五大产地机制砂的基本性能,研究了不同产地机制砂对UHPC性能的影响。结果表明:不同产地机制砂由于原石的不同,性能会存在一定差异,其中差异最为突出的是压碎值,最大相差高达80%;不同产地机制砂制备UHPC的7 d抗压强度在112.80~161.60 MPa间、28 d抗压强度在102.50~153.80 MPa间;不同产地机制砂制备UHPC的7 d抗折强度在22.00~29.10 MPa间、28 d抗折强度在22.80~29.20 MPa间;不同产地机制砂UHPC的微观结构和水化产物也存在一定差异,但微观结构基本为孔隙率较小的致密结构。在UHPC材料设计与质量控制中,应考虑机制砂产地的差异性。

The basic properties of five major local production regions of manufactured sand in Gansu were compared,and the impact of manufactured sand from different production regions on the performance of UHPC was studied.The results show that there are certain differences in the performance of manufactured sands from different production regions due to the different raw stones,among which the most prominent difference is the crushing value,with a maximum difference of 80%in the crushing value of manufactured sands from different production regions.The 7 d compressive strength of UHPC prepared with manufactured sands from different production regions ranges from 112.80 MPa to 161.60 MPa,and the 28 d compressive strength ranges from 102.50 MPa to 153.80 MPa.The 7 d flexural strength of UHPC prepared with manufactured sands from different production regions ranges from 22.00 MPa to 29.10 MPa,and the 28 d flexural strength ranges from 22.80 MPa to 29.20 MPa.There are also certain differences in the microstructure and hydration products of UHPC prepared with manufactured sands from different production regions,but the microstructure is basically a dense structure with low porosity.In UHPC material design and quality control,it is necessary to consider the differences of manufactured sands production regions.