自充填混凝土體積穩定性之監測與研究

Abstract

乾縮與潛變隨著當地材料的不同、環境因素以及試體尺寸的大小而有所影響。如：結構體受環境潮溼或乾燥時而收縮，結構體承受載重力量大小，溫度變化等而造成內部基材變形。長期下來，結構體會呈現大變形而嚴重影響其使用壽命。 本實驗環境控制在50％ R. H.、23℃之乾燥室，主要探討鋼筋用量、鋼筋號數、設計強度和養護時間對乾縮、基本潛變與乾燥潛變之影響性，並與傳統混凝土相比較。試驗發現，自充填混凝土有較強之比克作用，其乾燥潛變與乾燥狀況下之應力變形均較傳統混凝土高，此現象根據卜特蘭水泥與卜作嵐材料的水化作用之微觀機構、強度形成、緻密性及不同水化機理進行解釋。最後，期望從實驗數據所歸納出的乾縮與潛變相關函數式，能予以工程界正確地對結構體長期變形做預測。

The shrinkage and creep of concrete are affected by many factors, such as relative humidity, stress, temperature, constituent proportions. The deformation may because too large such that the performance may be reduced.

This study limits to RH at 50% and 23℃ environments. The parameters to be studied are the steel area, the diameters of steel, compressive strength, and the curing condition. The shrinkage, basic creep and shrinkage creep were studied for both self-compacting concrete(SCC) and ordinary concrete(OC). It is found that SCC shows a higher Pickett effect and the shrinkage and creep are higher than those of OC. It can be explained based on the mechanics of hydration. Finally, a regression equation were obtained for the prediction of shrinkage and creep.