不同矿物掺合料对干混砂浆性能的影响

Influence of different mineral admixture on the performance of dry-mixed mortar

节能节材和保护环境已成为可持续发展的主题,矿物掺合料在干混砂浆中的应用势在必行。采用粉煤灰、矿粉和过火煤矸石粉以及不同复合比例的矿物掺合料与水泥作为干混砂浆胶凝材料,研究其对干混砂浆性能的影响,结果表明:粉煤灰与矿粉在合适比例下,对早期强度贡献大,与单掺粉煤灰相比,7 d抗压强度提高5.9 MPa,但保水率差;与助剂过火矸粉在合适比例下,对后期强度和保水率贡献大,与单掺粉煤灰相比,28 d抗压强度提高6.9 MPa,保水率提高2.1%。经实践证明加入适量纤维素醚能大幅度提高砂浆的保水率。

Energy-saving and environmental protection has become the theme of sustainable development; therefore it is imperative that mineral admixture will be added in the dry-mixed mortar.The paper mainly studied different mineral admixture＇s influence on the perfor- mance of dry-mixed mortar.Fly ash, mineral powder, spontaneous combustible gangue, different compounded admixture and cement were used as gelled material of dry-mixed mortar.The results show that the compounded admixture of fly ash and mineral powder according to appropriate proportion make great contribution to the early strength of the dry-mixed mortar.Compared with the single fly ash, its compres- sive strength of 7 d increases 5.9 MPa, while the water retention make poor.The compounded admixture of fly ash and spontaneous com- bustible gangue added with grinding aids according to appropriate proportion make great contribution to the later strength and water reten- tion of the dry-mixed mortar.Compared with the single fly ash, its compressive strength of 28 d and water retention increase 6.9 MPa and 2.1%, respectively.It has been proved that the water retention of dry-mixed mortar can be greatly enhanced by adding cellulose ether.