Work

Experimental study on the effect of nano SiO2 dispersion on the compressive strength and early high-temperature resistance of modified cement paste

Year: 2024

Type: article

Abstract: This study investigates the influence of varying levels nano-silica (NS) dispersion levels on cement paste (CP) properties. Utilizing ultrasonic dispersion and water-reducing agent, NS was uniformly dispersed within the CP. This research methodically investigates the dispersion of NS and its subsequent effects on CP's mechanical properties, high-temperature resistance and microstructure. The findings demonstrated that effectively dispersed NS markedly improved CP's initial and residual compressive strength after high-temperature exposure. Optimal comprehensive performance of the cement paste was achieved with an ultrasonic dispersion duration of 40 min, an NS concentration of 1.0 wt%, and Polycarboxylate Ether concentration of 0.75 wt%. The 28-day compressive strength was 83.7 MPa, and the normalized residual compressive strength was 37.3 % after holding at 800 ºC for 2 h. Microstructure analyses indicate that optimal NS dispersion facilitates the early cement hydration process by filling minute voids and increasing the compactness of the cement matrix . This enhancement positively impacts CP's internal structure, mitigating crack formation and growth, thus enhancing compressive strength and high-temperature resilience.

Source: Case Studies in Construction Materials

DOI: 10.1016/j.cscm.2024.e04135

Authors: Zhang Xiaowei, Pei Xiaofang, Zhao Sheng, Shi Haoran, Wu Linsong

Institution: Yangtze University

Language: English

Topic: Concrete and Cement Materials Research

Subfield: Civil and Structural Engineering

Field: Engineering

Domain: Physical Sciences

SDG: Industry, innovation and infrastructure

Open Access status: gold

Estimated APC paid: $2,110