纤维素醚对衬砌混凝土力学与工作性能的影响OA

In this paper,the applicability of hydroxypropyl methyl cellulose ether(abbreviated as cellulose ether)in large-flow lining concrete was studied,and its influence on the fresh mixing properties,rheological properties and compressive strength of concrete was evaluated.The microscopic mechanism was revealed by means of TGA-DTG,SEM and nanoindentation.The results show that the thickening effect of cellulose ether leads to the decrease of slump and expansion of lining concrete,but effectively inhibits the time loss of lining concrete.The time loss of slump and expansion can be reduced by 75.0％and 66.7％respectively when the cellulose ether content is 0.12％(mass fraction),and the anti-segregation performance of lining concrete is improved.Cellulosic ether improves the anti-flowability of lining concrete,makes it more difficult to shear deformation,and shows stronger thixotropy and water retention capacity.The incorporation of cellulose ether has a positive effect on the compressive strength of lining concrete.The addition of 0.03％～0.12％cellulose ether can increase the 28 d compressive strength of lining concrete by 7.6％～23.6％.In addition,cellulose ether improves the hydration degree of cement,increases the content of hydration products,makes the microstructure of the sample surface denser,and increases the content of low density and high density calcium silicate hydrate(C-S-H)gel.Therefore,the comprehensive performance of lining concrete is improved.