Analysis of the influence of meshes used as reinforcement for mortar coating of facades on the tensile strength

ABSTRACT Displacement and fissures are recurrent pathological manifestations in the facade coating of brazilian buildings. In this context, it is known that mortar coating is still the most used in the civil construction market and has demonstrated several problems due to inappropriate employment and execution. Therefore, the present work aimed to evaluate the influence of different meshes as reinforcement for mortar coating, in order to identify which one present the best performance. It was used three mesh models, two made of galvanized metal with different meshes and thicknesses and one made of high-density polyethylene. In order to isolated characterize the meshes for tensile strength, it was performed the tensile assay in specimens of 250x300 mm for each mesh models. To evaluate the influence of the different meshes in conjunction with the mortar, the tensile test in bending at 4 points in specimens of 200x500 mm was carried out, where the meshes were inserted at 15, 25 and 30 mm from the bottom of the specimen with 50 mm thickness. The data indicate that the square 25x25 mm and 1.24 mm wire galvanized metal mesh presented the best performance among the tested models.

摘要：位移与裂缝是巴西建筑外墙饰面频发的病害表现。在此背景下，砂浆饰面仍是建筑工程市场应用最广泛的饰面形式，但因使用不当与施工不规范，已暴露出诸多问题。为此，本研究旨在评估不同增强网格对砂浆饰面的影响，以筛选出性能最优的网格方案。本次研究共采用三类网格模型：两款为具备不同网孔规格与丝径厚度的镀锌金属网格，另一款为高密度聚乙烯（High-Density Polyethylene）网格。为单独表征各网格的拉伸强度性能，针对每类网格模型制备250×300 mm规格的试样并开展拉伸试验。为评估不同网格与砂浆的协同作用效果，针对200×500 mm规格的试样开展四点弯曲试验，将网格分别置于距试样底部15 mm、25 mm及30 mm的位置，试样厚度为50 mm。试验数据显示，在所有受试网格模型中，丝径1.24 mm、网孔规格为25×25 mm的镀锌金属方形网格表现最优。