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烧结普通砖国家标准明确规定:抗冻性能必须合格。即将砖样浸水48小时,在-15℃以下冻融15次后,其干重损失不大于2%。如抗冻性能不合格,即使其它所有指标都符合规定,也视为废品。这一严格规定,主要是针对“黄砖”提出的。我国“三北”地区冬季气候寒冷,有较长一段时间在0℃以下。“黄砖”质地疏松,吸水率高,经过雨季砖内积存水分较多,冬季来临,砖内的水就会冻冰,当水结冰时体积膨胀,并产生一定压力,致使砖内颗粒组织位移,整体性遭到破坏,但仍冻结在一起;天气回暖化冻后,脱落的粘土颗粒就会呈现出风化掉皮的现象。年复一年墙面脱落砖屑日益严重,尤其是墙基和背阴处的砖,由于吸收地下水分和不易干燥,墙皮脱落尤为突出,更严重的是这种砖的强度明显降低,对建筑物的寿命威胁极大,如果是清水墙还会影响美观。所以冬季气候严寒和地下水位较高的地区,建房时
The national standard for sintered ordinary bricks clearly stipulates that the frost resistance must be qualified. The brick sample was soaked in water for 48 hours. After 15 cycles of freezing and thawing below -15°C, the dry weight loss was no more than 2%. If the frost resistance performance is unqualified, even if all other indicators are in compliance with the regulations, they are considered as waste products. This strict rule is mainly proposed for “yellow bricks.” China’s “Three North” region has a cold winter climate and has a long period of time below 0°C. “Yellow brick” has loose texture and high water absorption. After the rainy season, bricks contain more moisture. In winter, the water in the bricks freezes. When the water freezes, it expands in volume and generates a certain pressure, causing the granular structure in the brick. Displacement, the integrity has been destroyed, but still frozen together; after the weather warms up and freezes, the exfoliated clay particles will show the phenomenon of weathering and peeling. Year after year, the bricks on the wall are falling off, especially the bricks in the wall base and the shade, because of the absorption of groundwater and the difficulty in drying, the peeling of the wall is particularly prominent. The more serious is that the strength of this brick is significantly reduced. The life threat of the material is extremely great. If it is a clear wall, it will also affect the appearance. Therefore, in areas with severe winter weather and high groundwater levels, when building houses