【正文】 在 水泥的初凝時間內(nèi)為此 ，可將操作工人分成幾個作業(yè)組同時相 向或相背而行。試驗證明，防水混凝土早期脫水或養(yǎng)護(hù)過程缺水 ，將大幅度降低其抗?jié)B性能。t out of shape and stress not cause not free. Such as case roof beam roof concrete and guardrail concrete. This two kinds of temperature stresses draw back stresses caused to act on with the doing of concrete together frequently. It is a more plicated job to want to analyse the distribution , size of the temperature stress accurately according to known temperature. In case of great majority , need to rely on the model test or the number value to calculate. To is it make temperature stress have sizable limp to creep concrete, at the stress accounting temperature, must consider the influence that creep , calculate concretly that no longer states thinly here. Control and preventing the measure of the crack of 3 temperature For prevent crack , lighten temperature stress can from control temperature and is it is it set about to restrain terms from two to improve. The measure of controlling temperature is as follows: (1)Is it improve aggregate grade mix , is it do rigid concrete to spend , mix mixture to adopt, is it guide angry pharmaceutical or plastification pharmaceutical ,etc. measure in order to reduce cement consumption of concrete to add。s best. 3)Prevent the old concrete subcooling , in order to reduce the restraint among the old and new concrete. The early maintenance of the concrete, the main purpose lies in keeping the suitable warm and humid condition , in order to get the result of two respects, on the other hand make the concrete avoid the invasion and attack of the unfavorable and warm , humidity out of shape, the ones that prevent from harmfully are cold to contract and do to contract. On one hand make cement water function go on smoothly , is in the hope of reaching the intensity designed and resisting the ability of splitting. The suitable warm damp condition is interrelated. Mix warm keeping measure paid to congeal often protect wet results too. Analyse , water concrete include moisture can meet demand , cement of water have enough and to spare newly theoretically. But because the reason of evaporating etc. often causes losses of the moisture, thus postpone or hinder water of the cement from, the surface concrete receives this kind of adverse effect easiestly and directly. Key period when maintained in initial a few days after so the concrete is built, should pay attention to conscientiously in constructing. Conclusions Construction temperature and relation of crack in concrete the above carry on preliminary discussion of theory and practice, though the academia has different theories to origin cause of formation and puting technology of the concrete crack, but to concrete prevention and improving the measure suggestion to relatively unify , application in practice result fine too at the same time, concrete to is it observe , pare more more by us to want in constructing, analyse more , summarize more after going wrong , bine many kinds of prevention and deal with the measure, 18 the crack of the concrete can be avoided. control of waterproof concrete construction Combined with experience, from formwork design, fabrication and installation, assembing reinforoement, pouring and curing of concrete and other aspects construction technology of fairfaced concrete is introduced as well as quality control measures and standards in order to reduce engineering cost to acquire satisfied economic and social benefits. The factors of influening waterproof concrete quality are very many Any links does not pay attention to the waterproof concrete of field loss hinders the water function without exception jointly with construction in the basement adopts secondary form board fabrication and installation, reinforced bar fabrication and bind, concrete stirring and mixing system and transport, concrete concrete covibration beat with a stick, construction joint practice, concrete curing and dismantle model and beingready for backfill and so on are very critical to quality method to ensure that waterproof concrete self waterproof, and the way of practice has wan out. Method being under construction Fabrication and Installation According to the concrett of closely knit , demand of reason why to form board since the waterproof also concrete have made and have assembled corresponding rise is special , be to require that not leaving out thick fluid , firm closely knit block of wood deformation , water absorption Character should be small and ought to give priority to select and using bamboo slab rubber form board or the steel form.. Strict control form board room gap size, necessary exceeding 2 mms uses foam rubber or plastic to squeeze a crack in , porous form board nonutility 19 without exception to board face Be ready for wall post at the same time rotting the prevention and cure job Adopt the cement mortar pouring same ,indicia in before the root segment sticking the foam rubber or plastic strip , the bottom puts on a cement mortar , concrete a concrete, first 5 cm ~ 10 cm. Since waterproof, concrete structure wall thickness is mostly more infertile .Be to ensure that ponent geometry dimension , Chang adopt the inside and outside bolt to pull the measure meeting attention to, responds to on play receive bolt centre interpose stop water iron plate, to prevent water from forming pilotage passage along bolt leakage. Assembing reinforoement Waterproof concrete structure has demanding as follows to the reinforced bar 1) reinforced bar should adopt twisted steel as far as possible , increases by hold wrap a force posing in reply a water ability 2) reinforced bars connect should try one39。Crack 。 施工縫作法 8 施工縫是防水結(jié)構(gòu)的薄弱環(huán)節(jié)之一。 由于防水混凝土要求較高的密實性，所以拌制也要有較好的均勻性，為此應(yīng)做好如下幾點(diǎn)： 1)確保攪拌時間，每次攪拌從投料到出料一般不少于 2