Abstract:

     To study the influence of low-grade fly ash on the concrete strength and liquidity, three grades concrete of C20, C30 and C40 were prepared by using equal amount of fly ash to replace cement content of 0, 10%, 20% and 30% (mass fraction, the same below). The fluidity and strength of each number of concrete were tested. The results show that low-grade coal ash is advantageous to the liquidity of concrete. With the increase of the dosage of fly ash, 7d, 28d compressive and splitting tensile strength decreases gradually, 56d compressive and splitting tensile strength of C30 and C40 is closed to the reference concrete, but the 56d compressive strength of C20 concrete is different from that of reference concrete.

Key words: font-size: 10.5pt, mso-bidi-font-size: 12.0pt, mso-fareast-font-family: 宋体, mso-font-kerning: 1.0pt, mso-ansi-language: EN-US, mso-fareast-language: ZH-CN, mso-bidi-language: AR-SA"> font-size: 10.5pt, mso-bidi-font-size: 12.0pt, mso-fareast-font-family: 宋体, mso-font-kerning: 1.0pt, mso-ansi-language: EN-US, mso-fareast-language: ZH-CN, mso-bidi-language: AR-SA" lang="EN-US">fly ash, concrete, fluidity, strength