Admixing JM-SRA and permeating AS20 can all effectively reduce the dry shrinkage of RCC, and admixing JM-SRA have better results: it can reduce 60% dry shrinkage at 1d~3d, and reduce more than 35% dry shrinkage at 90d.
The block test specimen (100 mm×100 mm×515 mm) was formed using production equipment and raw materials (cement,stone ballast and modification material) of a concrete block factory. The influence of shrinkage-reducing agent,polypropylene fiber and expansion agent on strength and dry shrinkage of concrete block were systematically tested.
By indoor experiments the dry shrinkage and temperature shrinkage characteristic of powdered soil are systemically researched. And it shows the shrinkage index of powdered soil stabilized by lime and solidification CLG powder are bigger than that by cement and solidification SS-108. Futhermore,the shrinkage index of powdered soil stabilized by binder and solidification increase with more binder.
Based on the study of fundamental law of temperature and dry shrinkage of fibre reinforced semi-rigid materials, the basic thought、method and appraisement index of crack-resisting design of fibrous reinforcement soil materials are discussed in this paper.
Our research results have shown that the various shrinkage of concrete cause concrete cracking in building engineering, such as autogenous shrinkage, dry shrinkage, temperature shrinkage, plastic shrinkage, carbonized shrinkage, etc.
Abstract: Studies of the physical characteristics of the superior clone Chinese fir(19 years)(Cunninghamia lanceolata),which grow in Jingdong Forest Farm,show that its basic density,dry shrinkage of radial,chordwise and volume are 0.279 g·cm~(-3),(2.90%),5.10% and 7.85% respectively;
对金洞林场杉木无性系19年生(不含苗龄)的木材物理性质研究,结果表明:杉木优良无性系木材的基本密度、径向干缩率、弦向干缩率、体积干缩率分别是0.279 g. cm-3、2.90%、5.10%和7.85%;
Orthogonal experiments indicated that,compared with ordinary mortar,ratio of flexural to compressive strength for powdered polymer-modified mortar increased by 69%,bonding strength enhanced by 22.48 times,Maximum penetra- tion pressure rose by 6 quantitative levels,moisture loss dropped by 34.8%,dry shrinkage reduced by16%,thus markedly improving performance of the mortar.
but those of the check-group CK are 0.275 g·cm~(-3),2.80%,5.10% and 8.00% respectively. The basic density of wood is an important index to indicate its strength and estimate its mechanical property or technique while the stability and flexibility of its dimension can be judged with the dry shrinkage of wood.
而对照CK的基本密度、径向干缩木材基率、弦向干缩率、体积干缩率分别是0.275 g. cm-3、2.80%、5.10%和8.00%.
Starting from the study of shrinkage mechanism in this paper,when 7% of rare earth dust(XF) was added,remarkable green effect was produced; not only 49%～88% of the compressive strength was increased but dry shrinkage value for every age was decreased also,and the ultimate rate of dry shrinkage decreasing by 18%.
Gypsum-based Outer wall plastering material (SVF) is a new type of plastering material. It has a lot of specific characteristics, such as good construction property, rapidly hardening, high bonding strength and small dry shrinkage.
Gypsum based outer wall plastering material (SVF in short) is a new energy saving outer wall plastering material. It has good construction property, quick hardening speed, high bonding strength and little dry shrinkage.
AEA is a high efficiency excellent quality and energy-saving concrete expansion agent with low alkalinity, large expanding energy, small additive and dry shrinkage, high late strength of concrete. It has very good shrinkage compensation and long stability.
This paper describes the properties of Concrete added CEA expansion admixture,include larger expansion rate,small dry shrinkage and good cracking resistance. Adding fly ash and CEA can improve concrete strength and property of interface intermediate layer,permeability.
Results show that the GBC concrete has lower dry shrinkage and higher anti-crack property than that of OPC,that the GBC mortar has better resistance to sulfate attack,and that the GBC concrete has excellent ability to resist erosion of chloride ion with a low diffusion coefficient.