|
The transition zone in normal concrete has been studied in detail by various researchers and is confirmed to be the weakest zone [11, 12, 13, 14 and 15]; the weakness being attributed to the higher porosity at the interface as a result of the clogging of bleed water, formation of larger crystal particles of hydration, and deposition of calcium hydroxide crystals with preferential orientation. The interface in normal concrete is one between a very strong aggregate phase and a less strong matrix, whereas in lightweight aggregate concrete, the matrix is stronger than the aggregate. Since lightweight aggregates are generally porous, the cement hydration products and bleed water may permeate into the pores of the aggregate rendering the transition zone less porous than that of normal concrete [16]. In similar lines, for aerated concrete, the transition zone is between a relatively strong matrix and zero strength voids and thus will be denser and more homogeneous than the interfaces in both normal and lightweight aggregate concrete. The possible reasons for such reduction in interfacial porosity are:
1. During the process of aeration, the gas formed due to the chemical reaction (which later forms the voids) constricts the matrix;
2. The bleed water is free to move in the interface because of the absence of aggregates and the presence of large voids;
3. The absence of the aggregates allows (a) unrestricted space for hydration and growth of crystals and (b) random orientation of the crystals at the interface, resulting in better interlocking.
Also, the transition zone in aerated concrete will be denser than its bulk paste since the bulk paste essentially has pores of varying sizes. Though the structure appears similar, the transition zone in aerated concrete is likely to be significantly different from that in normal concrete as far as its influence on the properties is concerned. An in-depth characterization of this zone would be helpful in understanding the material better. 过渡区的普通混凝土已详细研究了不同的研究人员和被确认为是最薄弱的区域[ 11 ， 12 ， 13 ， 14和15 ] ;的弱点被归因于较高的孔隙率的界面上，由于堵塞流血水，形成较大的晶体颗粒的水化，并沉积氢氧化钙晶体的择优取向。听听小本创业好项目。该接口在普通混凝土是一个非常强大的汇总阶段，并不太强大的矩阵，而在轻骨料混凝土，矩阵较强的总和。由于重量轻集料一般是多孔的水泥水化产物和流血水渗透到毛孔的总和使过渡区少多孔比普通混凝土[ 16 ] 。在类似的线，为加气混凝土，看着小本创业故事——一分钱菠萝引发的创业奇想。过渡区之间的一个相对强大的矩阵和零强度空隙，从而将更多的密度和均匀的界面比正常和轻骨料混凝土。的可能原因，例如减少界面孔隙率是： 1 。在这个过程中曝气，气体形成的原因是化学反应（后来形式空隙） 限制的矩阵; 2 。流血水的自由行动中的接口，因为没有总量和存在大量的空白; 3 。缺席的情况下总量允许（ a ）不受限制地空间和增长的水化晶体和（ b ）随机取向晶体的界面上，从而更好地相互联系。 此外，过渡区的加气混凝土将其大部分密度比贴贴以来的大部分基本上已毛孔大小不同。虽然类似的结构，过渡区的加气混凝土很可能会显着不同，在普通混凝土至于它的影响力的性质而言。深入表征这个区域将有助于更好地理解材料。 (责任编辑：admin) |
豫ICP备10206634号