工程弃土免烧砖技术路径与发展趋势

Technology Path and Development Trend of Nonsintered Bricks with Construction Spoil

国内工程弃土排放量大,但资源化利用率较低,而使用工程弃土制备免烧砖是一种可行的高附加值途径。首先,介绍了工程弃土的分类与主要处置方式,指出工程弃土原料低碳脱水与工艺参数难以确定等瓶颈问题。其次,介绍了免烧砖常用的生产流程以及成型、养护等工艺对免烧砖性能的影响,进一步分析了胶凝材料类型与掺量、含水率、外加剂等因素对免烧砖力学性能的影响规律,同时总结了弃土免烧砖的资源再利用与低碳优势;指出了表面光滑、不易与砂浆结合、抗剪强度低、干缩变形大等缺陷。最后,从绿色建筑的角度出发,提出弃土免烧砖的未来研究方向。

The amount of domestic construction spoil emission is significant,but the resource utilization rate is low.One feasible and high value-added way to utilize construction spoil is to produce nonsintered bricks.Firstly,the classification and main disposal methods of construction spoil are introduced,and the bottlenecks such as low-carbon dewatering of construction spoil raw materials and the difficulty of determining the process parameters are pointed out.Then,the common production process of nonsintered bricks along with the influence of molding,curing and other processes on the performance of nonsintered bricks are introduced.Next,the type of cementitious material and mixing,moisture content,admixtures and other factors on the mechanical performance of nonsintered bricks are further analyzed,and the resource reuse and low-carbon advantages of nonsintered bricks are summarized.The defects such as smooth surface not easy to combine with mortar,low shear strength,large dry shrinkage deformation,etc.are also reviewed.Finally,the future direction of research on nonsintered bricks from the perspective of green building is put forward.