低品质粉煤灰木质素纤维复合抹灰砂浆的性能研究

发布时间：2018-04-11 06:46

本文选题：抹灰砂浆 + 性能　；参考：《宁夏大学》2017年硕士论文

【摘要】：随着当代建筑的迅速发展,抹灰砂浆对和易性、粘结性及抗裂性的要求越来越高,将各种掺合料掺加到抹灰砂浆中的探究,已成为当前研究的热点。宁夏地区许多的低品质粉煤灰没有得到充分利用,堆放在灰场,既占用场地又污染环境。如何有效提高低品质粉煤灰的利用率受到关注。低品质粉煤灰掺加到混凝土中的研究取得了可喜成果,如低品质粉煤灰可提高混凝土的抗拉和抗折性能,但将低品质粉煤灰用于抹灰砂浆的相关研究较少,抹灰砂浆无筋且强度要求低,将低品质粉煤灰用于抹灰砂浆,能够满足强度要求,因此本文提出了低品质粉煤灰在抹灰砂浆中的研究这一课题,以期有效利用低品质粉煤灰,改善抹灰砂浆的性能提供参考依据。本论文以M15砂浆为研究对象,以水胶比、低品质粉煤灰取代率、低品质粉煤灰超掺率和木质素纤维掺量为因素,设计正交试验方案L16(45),探索了低品质粉煤灰木质素纤维复合抹灰砂浆性能的研究。试验结果表明:(1)对于抹灰砂浆的和易性,低品质粉煤灰取代率、低品质粉煤灰超掺率和木质素纤维掺量能够明显改善抹灰砂浆的和易性,低品质粉煤灰取代率和超掺率可提高砂浆的流动性;木质素纤维可提高砂浆的保水性。(2)对于抹灰砂浆的力学性能,低品质粉煤灰取代率,对砂浆的强度表现为负效应,对抗压强度和拉伸粘结强度的影响较大,但对劈裂抗拉强度的影响较小;超掺低品质粉煤灰可以增强砂浆的强度,对于抗压强度和劈裂抗拉强度,合理的超掺能够补偿取代对强度造成的损失;木质素纤维良好的保水性和吸水性,能够增强抹灰砂浆的强度,对拉伸粘结强度和劈裂抗拉强度的增强效应明显。(3)对于抹灰砂浆的干燥收缩变形,低品质粉煤灰取代率和木质素纤维能有效抑制砂浆的干燥收缩,超掺低品质粉煤灰使砂浆的收缩变形略微增大,但影响不显著。(4)应用最小二乘法建立了各因素对抹灰砂浆的和易性、力学性能及干燥收缩特性的多元非线性回归模型,显著性高,相关性好。研究结果对宁夏地区劣质粉煤灰综合利用,改善抹灰砂浆和易性、粘结性及抗裂性具有重要的现实意义。
[Abstract]:With the rapid development of contemporary architecture, the requirements of plastering mortar for easiness, adhesion and crack resistance are becoming higher and higher. The research of adding various admixtures to plastering mortar has become a hot research topic at present.Many of the low quality fly ash in Ningxia are not fully utilized and are stacked in the ash yard, which not only occupies the site but also pollutes the environment.How to effectively improve the utilization ratio of low quality fly ash has attracted much attention.The research of adding low quality fly ash to concrete has achieved gratifying results. For example, low quality fly ash can improve the tensile and flexural properties of concrete, but there is little research on the application of low quality fly ash to plastering mortar.Plastering mortar has no reinforcement and low strength requirement. Using low quality fly ash in plastering mortar can meet the strength requirement. Therefore, the research of low quality fly ash in plastering mortar is put forward in this paper, in order to utilize low quality fly ash effectively.Improving the performance of plastering mortar provides reference basis.In this paper, M15 mortar is taken as the research object, the water / binder ratio, the replacement rate of low quality fly ash, the superaddition rate of low quality fly ash and the content of lignin fiber are taken as the factors.The orthogonal test scheme L1645 was designed to study the properties of low quality fly ash lignin fiber composite plastering mortar.The experimental results show that the compatibility of plastering mortar, the substitution rate of low quality fly ash, the superaddition rate of low quality fly ash and the content of lignin fiber can obviously improve the easiness of plastering mortar.Low quality fly ash substitution rate and superaddition rate can improve the fluidity of mortar, lignin fiber can improve the water-retaining property of mortar, and the mechanical properties of plastering mortar, the substitution rate of low quality fly ash and the strength of mortar are negative effects.The influence on the compressive strength and tensile bond strength is greater, but the effect on the splitting tensile strength is small, the strength of mortar can be enhanced by adding low quality fly ash, but the compressive strength and splitting tensile strength can be enhanced.Reasonable overmixing can compensate for the loss of strength caused by replacement; lignin fiber has good water retention and water absorption, which can enhance the strength of plastering mortar.The strengthening effect on tensile bond strength and splitting tensile strength is obvious. The dry shrinkage deformation of plastering mortar is obvious. The replacement ratio of low quality fly ash and lignin fiber can effectively inhibit the drying shrinkage of mortar.The shrinkage and deformation of mortar is slightly increased by adding super low quality fly ash, but the influence is not significant. (4) the multivariate nonlinear regression model of the various factors for the easiness, mechanical properties and drying shrinkage characteristics of plastering mortar is established by using the least square method.The significance is high and the correlation is good.The results have important practical significance for comprehensive utilization of inferior fly ash, improvement of plastering mortar and easiness, adhesion and crack resistance.
【学位授予单位】：宁夏大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU578.1

【参考文献】