Effect Of Admixture On Performance When Droping Only Or Mixed With The Other Admixture Under Steam Curing

Facing with an increasingly complicated engineering environment,it makes higher demands of the concrete about its performance,steam curing which can be ofen used in prefabricated concrete components could improve the early strengh of concrete effectively,and it could create some economic effects by accelerating the circulation of moulds and the productivity?In the many study of scholars single doping admixture seems usual and also had made certain achievements in scientific research,however the studies of mixing with two or more aspects of admixture are not deep enough and the systematic?Superplasticizer?early strenth agent?air entraining agent,expansive agent retarder will be used in this project,and take superplasticizer mixed with them,by measuring hydration temperature peak and its appearing time,hydration heat,production of Ca(OH)2,using direct thermometry and X-ray diffraction technique we can study the effects of the single and double doped admixture on the process of cement hydration and conrete strength under steam curing?The results show : single droping Superplasticizer of aliphatic sulfonate formaldehyde condensate can postpone hydration temperature peak's appearing time in the process of cement hydration under the steam curing,it also reduces hydration heat,compressive strength is on a downward trend under the provisions of the steam curing system,XRD analysis showed that with the presence of such Superplasticizer reduce production of Ca(OH)2?Single droping naphthalene superplasticizer advance hydration temperature peak's appearing time,increase hydration heat,Its steam curing strength also appeared to improve,the production of Ca(OH)2 will increase in the process of cement hydration?Single droping early strenth agent potassium sulfate,sodium chloride,calcium formate will advance hydration temperature peaks appearing time,increase hydration heat and Its steam curing strength,analysis of results show that of these three kinds of early strenth agent can increase the production of Ca(OH)2 ?After droping retarder polyvinyl alcohol,sucrose,tartaric acid alone they all can postpone hydration temperature peak's appearing time,reduces hydration heat,and to effects of the strength of steam curing tartaric acid has little effects,sucrose has greater influence?After droping air entraining agent rosin sodium and saponins powder alone hydration temperature peak's appearing time will changed with the increase of its content,both of them have little effects on the hydration heat,but they will make the steam curing strength a substantial decrease?droping expansive agent alone will advance hydration temperature peak's appearing time,steamcuring strength will increase in a certain dosage range but have little effects on hydration heat?Studying its effect on the strength of steam curing concrete after mixing the superplasticizer with admixtures,the results show:when droping superplasticizer(aliphatic sulfonate formaldehyde condensate,naphthalene superplasticizer)into the early strenth agent potassium sulfate,sodium chloride,calcium formate respectively steam curing strength decrease ?When droping superplasticizer into retarder polyvinyl alcohol,sucrose,tartaric acid respectively steam curing strength will aslo decrease,but the width of decrease have some differences ?If air entraining agent rosin sodium,saponins powder mixed with aliphatic sulfonate formaldehyde condensate steam curing strength decrease slightly compared with droping air entraining agent alone,but it will appears slightly increase after droping the naphthalene superplasticizer into air entraining agent?...