利用废弃粘土砖制备泡沫混凝土的试验研究

发布时间：2018-11-09 19:41

【摘要】：随着建筑行业快速稳定发展，大量砖混结构建筑物被新型建筑物代替，拆除的废弃粘土砖成为难以处理的建筑垃圾。废弃粘土砖经过分拣、破碎、磨细等手段，可以得到再生废砖骨料和再生胶凝材料砖粉，废砖粉在激发剂作用下有较好的活性，适用于泡沫混凝土砌块等墙体材料。本文针对影响废砖泡沫混凝土性能的泡沫剂体系组成、胶凝材料体系组成、激发剂体系组成、外加剂等主要因素，采用室内试验及理论分析的方法，得到满足泡沫混凝土行业标准的最佳配合比，以及干表观密度、28d立方体抗压强度、干缩率、吸水率与冻融指标、碳化指标等大量试验数据。主要得到以下结论：选用十二烷基苯磺酸钠作为发泡剂，稀释比例为1:50，羟丙基甲基纤维素醚作为稳泡剂，掺入比例为0.12%，泡沫性能符合要求，可以用于废砖泡沫混凝土中；碱或硫酸盐能激发砖粉中的活性成分，当掺入15%石膏和20%石灰时，废砖泡沫混凝土力学性能优于其他激发剂组成；聚羧酸高效减水剂与废砖泡沫混凝土适应性良好，当其掺量在0.9%~1.5%之间时，废砖泡沫混凝土工作性好，干表观密度达到设计值；胶凝材料组成是影响废砖泡沫混凝土力学性能和吸水率的主要因素，当胶凝材料水泥:砖粉:粉煤灰为70:10:20时，废砖泡沫混凝土28d抗压强度大于5.5MPa，考虑到最大程度使用工程废弃物，采用水泥:砖粉:粉煤灰为60:20:20的组成，此时废砖泡沫混凝土28d立方体抗压强度不小于4.0MPa；废弃粘土砖作为细骨料掺入泡沫混凝土中时，可制备符合泡沫混凝土行业标准FC A10-C2-W20-JG/T266-2011的砂系废砖泡沫混凝土，，节约水泥147kg/m3，节约砂223.3kg/m3。试验制备出符合泡沫混凝土行业标准FCA06-C4-W25-JC/T266-2011的废砖泡沫混凝土，干表观密度635.1kg/m3，28d立方体抗压强度4.6MPa，吸水率24.0%，冻融后质量损失3%、强度损失18%，碳化系数0.87，导热系数0.127，性能符合GB0574-2010《墙体材料应用统一技术规范》中A3.5的要求，可用作外墙保温材料或填充墙等，与同密度等级传统泡沫混凝土相比节约水泥100kg/m3，不仅响应国家近年来建筑材料节能利废的政策号召，而且具有突出的产品经济效益和社会效益，应用前景广泛。
[Abstract]:With the rapid and stable development of the construction industry, a large number of brick and concrete structures have been replaced by new buildings. After sorting, crushing and grinding waste clay bricks, recycled brick aggregate and reclaimed cementitious brick powder can be obtained. The waste brick powder has good activity under the action of activator, and is suitable for wall materials such as foam concrete block. In this paper, the composition of foaming agent system, the composition of cementitious material system, the composition of activator system and admixture, etc., which affect the properties of foamed concrete with waste brick, are analyzed by laboratory test and theoretical analysis. The optimum mix ratio, dry apparent density, 28d cube compressive strength, dry shrinkage rate, water absorption, freeze-thaw index, carbonation index and so on were obtained. The main conclusions are as follows: sodium dodecylbenzene sulfonate was selected as foaming agent, the dilution ratio was 1: 50, hydroxypropyl methyl cellulose ether was used as foaming stabilizer, the proportion of sodium dodecyl benzene sulfonate as foaming agent was 0.12. Can be used in waste brick foam concrete; When 15% gypsum and 20% lime were added, the mechanical properties of waste brick foam concrete were superior to those of other activators. The polycarboxylic acid superplasticizer has good adaptability to waste brick foam concrete. When the content of polycarboxylic acid superplasticizer is between 0.9% and 1.5%, the waste brick foam concrete has good workability and dry apparent density reaches the design value. The composition of cement material is the main factor that affects the mechanical properties and water absorption of waste brick foam concrete. When cement: brick powder: fly ash is 70:10:20, the compressive strength of waste brick foam concrete is more than 5.5 MPA. Considering the maximum use of engineering waste, the cement: brick powder: fly ash is composed of 60:20:20, and the compressive strength of waste brick foam concrete is not less than 4.0MPa for 28d. When waste clay brick is mixed into foamed concrete as fine aggregate, sand series waste brick foam concrete conforming to FC A10-C2-W20-JG/T266-2011 standard of foam concrete industry can be prepared, which can save 147kg / m ~ 3 cement and 223.3kg / m ~ 3 sand. The waste brick foam concrete conforming to the industry standard of foam concrete (FCA06-C4-W25-JC/T266-2011) was prepared. The dry apparent density was 635.1 kg / m 328d cube compressive strength was 4.6 MPA, the water absorption was 24.0%, and the mass loss after freezing and thawing was 3%. Strength loss 18, carbonization coefficient 0.87, thermal conductivity 0.127. The performance meets the requirements of A3.5 in GB0574-2010 uniform Technical Specification for the Application of Wall Materials, and can be used as thermal insulation material for external walls or filled walls, etc. Compared with the traditional foam concrete of the same density grade, cement is saved by 100 kg / m ~ (3), which not only responds to the policy call of building materials in recent years to save energy and benefit from waste, but also has outstanding economic and social benefits, and has a wide application prospect.
【学位授予单位】：内蒙古科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TU528

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