由于做工不佳而导致的6个砖砌缺陷

18.luck新利 |2016年10月7日|Building Construction,Construction|暂无评论

DEFECTS IN BRICKWORK

工艺对砌体强度的影响

砖石公司拥有工匠建造的悠久传统，而无需对这种用于钢筋混凝土结构的工程监督。因此，经常被认为是一种结构材料，并且比混凝土更高的安全因子。当然，对此有一些理由，因为如果监督不存在，则任何结构性因素（无论是砌体还是具体）都将是不确定的。另一方面，如果将相同的监督应用于砌体与混凝土所需的相同水平，则砌体将与混凝土一样可靠。因此，对于在砌体中设计和构建的工程师来说，要对工艺因素进行欣赏，这些工艺因素在开发指定强度方面具有重要意义。通过对已知内置缺陷的墙壁进行测试，并将结果与没有缺陷的墙壁上的相应测试进行比较来获得此信息。在实践中，这些缺陷将在某种程度上存在，并且在不令人满意的工作中，它们的组合可能导致墙壁的压缩程度仅为应有的一半。但是，这样的墙显然会很糟糕，并且将远远超出任何合理的规范，以至于非常不可接受。

当然，在首先要适当地建造砖石，工程师花费的时间解释了以下对砖或块层的重要性，他的直接主管将是时间。

由于做工而导致的砖砌缺陷

1.未能填充床关节

必须完全填充砖砌的床接头。迫击炮床中的间隙可能仅是由于粗心或仓促而导致的，或者是由称为“皱眉’, which means that the bricklayer makes a gap with his trowel in the middle of the mortar bed parallel to the face of the wall.Tests show that incompletely filled bed joints can reduce the strength of brickwork by as much as 33%.

Failure to fill the vertical joints has been found to have very little effect on the compressive strength of brickwork but does reduce the flexural resistance. Also, unfilled perpendicular joints are undesirable from the point of view of weather exclusion and sound insulation as well as being indicative of careless workmanship generally.

2.Bed joints of excessive thickness

Increase in joint thickness has the effect of reducing masonry strength because it generates higher lateral tensile stresses in the bricks than would be the case with thin joints. Thus,16-19毫米厚度的床接头将使抗压强度降低30％，而10mm厚的接头则将降低。

3.Deviation from verticality or alignment

由俯卧撑或与墙壁不符的铅板建造的墙壁会导致偏心载荷，从而导致强度的降低。因此a wall containing a defect of this type of 12–20 mm will be some 13–15% weaker than one which does not。

4。铺设后暴露于不利天气

新铺设的砖瓦应受到防止过多或冰冻条件的保护，直到砂浆固化为止。通过蒸发或暴露于炎热的天气会过多的水分损失可能会阻止水泥完全保湿，从而导致无法发展砂浆的正常强度。结果，壁的强度可能会降低10％。冻结会导致壁从垂直方向移动，并相应地降低强度。Proper curing can be achieved by covering the work with polythene sheets, and in cold weather it may also be necessary to heat the materials if bricklaying has to be carried out in freezing conditions。

5。未能调整砖块的吸力

如果必须使用高吸收砖建造细长的墙，则可能会出现更细微的缺陷。原因在于图。1, which suggests how a bed joint may become ‘枕头’ shaped if the bricks above it are slightly socked as they are laid. If water has been removed from the mortar by the suction of the bricks, it may have become too dry for it to recover its originally flat shape. The resulting wall will obviously lack stability as a result of the convex shape of the mortar bed and may be as much as 50% weaker than should be expected from consideration of the brick strength and mortar mix. The remedy is to在铺设之前将砖块弄湿，以便将其吸力降低到2kg/m以下²/min，砂浆混合物中的石灰比例将有助于将水保留在砖块上。

6。砂浆的不正确比例和混合

The effect of mortar strength on the strength of masonry may be judged from图2from which it may be seen with bricks having a crushing strength of 30 N/mm²从11 n/mm降低了砂浆强度²to 4.5 N/mm²may be expected to reduce the brickwork strength from 14 N/mm²到11N/mm²。这对应于迫击炮混合物的变化1：3cement : sand to1：4.5or about 30% too little cement in the mix. A reduction in mortar strength could also result from a relatively high water/cement ratio whilst still producing a workable mix. It is therefore important to see that the specification for mortar strength is adhered to although there is an inherent degree of tolerance sufficient to accommodate small errors in proportioning and mixing the mortar. The use of unsuitable or an excessive amount of plasticizer in place of lime will produce a porous and possibly weak mortar and has to be guarded against.