污泥气化渣包覆骨料混凝土的单轴受压性能及其破坏模拟

Uniaxial Compression Performance and Failure Simulation of Aggregate Concrete Coated with Sludge Gasification Slag

摘要:

污泥气化渣(Sludge Gasification Slag,SGS)是污泥经过热解气化后产出的残渣,自身轻质多孔但强度较低,考虑对其进行包覆强化后可用作混凝土轻骨料。本研究使用水泥复合粉煤灰作为胶凝材料,对污泥气化渣进行包覆处理并将其用于轻骨料混凝土制备,研究了粗骨料类型和体积含量对混凝土性能的影响。采用有限元软件建立了混凝土二维数值模型,模拟了单轴受压条件下混凝土破坏时的损伤分布和应力-应变曲线。结果表明,胶凝材料包覆可在保持污泥气化渣轻质特性的基础上显著提升其筒压强度；当粗骨料体积分数相同时,污泥气化渣包覆骨料混凝土相比于污泥气化渣混凝土,单轴抗压强度提升了近2倍,达到了页岩陶粒混凝土的90%。当粗骨料体积分数为40%时,污泥气化渣包覆骨料混凝土的损伤区域最小,抗压性能最优。

Abstract:

Sludge Gasification Slag (SGS) is the residue produced after sludge pyrolysis and gasification, which is light and porous but has low strength. It is considered to be used as lightweight aggregate after coating and strengthening, and it is applied to lightweight aggregate concrete. In this study, cement composite fly ash was used as a cementing material to cover the sludge gasification slag after crushing and screening, and the coated sludge gasification slag was used to prepare lightweight aggregate concrete. The influence of coarse aggregate type and volume content on the performance of concrete was studied, and the comparison was made with uncoated sludge gasification slag and commercially sold gravel shale ceramics. A two-dimensional numerical model of concrete was established by finite element software to simulate the damage distribution and stress-strain curve of the concrete under uniaxial compression, and the feasibility of applying the aggregate coated with sludge gasification slag to lightweight aggregate concrete was discussed. The results show that the coating can significantly improve the cylinder compressive strength while maintaining the lightweight characteristics of sludge gasification slag. When the volume content of coarse aggregate is the same, the uniaxial compressive strength of Sludge Gasification Slag Coated Aggregate Concrete (SCLAC) is nearly 2 times higher than Sludge Gasification Slag Concrete (SGSC), up to 90% of Reference Shale Ceramics Concrete (RSCC). When the volume content of coarse aggregate is 40%, the damage area of SCLAC is the smallest and the compressive performance is the best.