Time dependent behaviors of concrete with various powder materials | |
| Author | Surapong Uttama |
| Call Number | AIT Thesis no. ST-99-20 |
| Subject(s) | Concrete--Additives Concrete--Testing Concrete--Additives Concrete--Testing |
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering. |
| Publisher | Asian Institute of Technology |
| Abstract | Powder materials have many influences on time-dependent behaviors of concrete. In this study, effects of shrinkage, compressive and tensile strength, thermal crack occurrence and creep prope1ty to thermal crack resistance of slag concrete are investigated. Shrinkage of m01tars with different curing conditions and distinct water binder ratio is measured along one month. Insufficient curing contributes to both large drying and autogenous shrinkage pa1ticularly in slag m01tar. However, water binder ratio has insignificant effect to total shrinkage in case of enough curing. In order to study influence of slag to tensile strength, tests for compression and tension of slag m01tars with various replacement ratios are performed. Although the autogenous shrinkage is prevented, the reduction of tensile and compressive strength of slag m01tar with high replacement level occurs. In addition, in case of large amount of slag, calculated tensile strength coincides with only splitting tensile strength but disagree with direct tensile strength. Therefore, the prediction of thermal crack occurrence of slag concrete by using the calculated tensile strength is not precise and the strength model need further development to cover this problem. In pait of thermal crack occurrence, simulation of thermal crack due to external confinement for slag paste is conducted at different curing temperatures. Thermal crack, which leads to reduction of tensile strength, takes place only at sufficient high temperature i.e., more than 40 degrees centigrade but the tensile strength reduction of slag paste is not as sharp as normal one. For creep test, sustained load 0.2fc' is applied to slag m01tars for one month with different curing conditions. Creep and shrinkage of slag m01tars have the similar patterns and become the largest in drying condition. Numerical prediction for shrinkage of slag concrete is verified. The shrinkage model used cannot accurately predict shrinkage of slag concrete with insufficient curing. Concept of solidification model is proposed and can explain deformation mechanism of shrinkage and creep as well as thermal crack occurrence clearly. |
| Year | 1999 |
| Type | Thesis |
| School | School of Engineering and Technology |
| Department | Department of Civil and Infrastucture Engineering (DCIE) |
| Academic Program/FoS | Structural Engineering (STE) /Former Name = Structural Engineering and Construction (ST) |
| Chairperson(s) | Kishi, Toshiharu;Kishi, Toshiharu; |
| Examination Committee(s) | Nii, Kazuyoshi;Pichai Nimityongskul; |
| Scholarship Donor(s) | AIT Patial Scholarship.; |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 1999 |