Effect of an expansive agent on mechanical behavior and durability performance of RC members | |
| Author | Suttichai Kittiwuttichusinp |
| Call Number | AIT Thesis no. ST-99-1 |
| Subject(s) | Expansive concrete Building materials--Service life Expansive concrete Building materials--Service life |
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering. |
| Publisher | Asian Institute of Technology |
| Abstract | Expansive agent is a kind of admixture added to Portland cement concrete to make it expansible. The effectiveness of expansive component regarding to mechanical behavior as well as durability performance of RC beam has been thoroughly investigated. From mechanical point of view, change of failure mode of flexural member from ductile to brittle has been reported due to severe drying under marginal design. This devaluation in mechanical performance under drying shrinkage has been shown recovered by the appropriate use of expansive agent as a part of cement replacement, both in case of normal concrete (compressive strength around 350 kgf/cm2 ) and high-performance concrete (compressive strength around 800 kgf/cm2 ) . In case of normal concrete (NC), expansive component is found to partially compensate the effect of severe drying shrinkage especially in pre-yielding range. In case of high-performance concrete (HPC), it is found to overcome the effect of drying shrinkage. The phenomenon of re-expansion, which is common in low w/b ratio concrete, is found to enhance the ductility slightly. So, it is thought that reexpansion might improve the shear capacity in pre-yielding range. Experimentally, the ductility of concrete beam is found promoted by expansion and re-expansion of expansive agent rather than load carrying capacity. Durability performance with re-expansion of expansive concrete is examined in terms of corrosion resistance. Calculated rust areas from experiment on low w/b ratio, NC beams show that the re-expansion of expansive agent can retard the progression of corrosion. Crack width measured monthly indicates the re-expansive progress. |
| Year | 1999 |
| Type | Thesis |
| School | School of Engineering and Technology |
| Department | Department of Civil and Infrastucture Engineering (DCIE) |
| Academic Program/FoS | Construction Engineering and Infrastructure Management (CM) |
| Chairperson(s) | Kishi, Toshiharu;Kishi, Toshiharu; |
| Examination Committee(s) | Kazuyoshi, Nii;Pichai Nimityongskul; |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 1999 |