Utilization of Mae-Moh fly ash as cement replacement material to reduce autogeneous shrinkage | |
| Author | Tinapat Sudsangiam |
| Call Number | AIT Thesis no. ST-93-24 |
| Subject(s) | Fly ash Concrete--Expansion and contraction |
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering, School of Engineering and Technology |
| Publisher | Asian Institute of Technology |
| Abstract | This research deals with some test results on the application of Mae-Moh fly ash to reduce autogeneous shrinkage of concrete and also the prediction of autogeneous shrinkage in concrete from paste by using a proposed model. Measurement of autogeneous shrinkage were conducted on cement paste samples. The parameters varied in the tests are types of fly ash, cement replacement percentages, and curing conditions. Flexural strengths, compressive strengths and setting times were determined for pastes with and without fly ash, in order to derive a basic data for judging the suitability of using Mae-Moh fly ash as a pozzolan. From the test results, it was found that both samples of Mae-Moh fly ash were effective in reducing autogeneous shrinkage, and therefore improving the flexural strength of the specimens. This was caused by expansion which occurred in the samples containing Mae-Moh fly ash. For the tested range, the higher the replacement percentage, the more the reduction in autogeneous shrinkage. Mae-Moh fly ash containing higher 503 content was more effective than that containing lower. The curing conditions were essential in controlling the efficiency since the expansion process required water. The pozzolanic activity index of Mae-Moh fly ashes was higher than that of fly ash from Hong Kong, therefore, higher 28-day compressive strength in paste with Mae-Moh fly ash than that from Hong Kong was observed. The setting times of pastes with Mae-Moh fly ash were shorter than those of the paste with fly ash from Hong Kong. It can be, therefore, concluded that both tested samples of Mae-Moh fly ash can be applied as pozzolana to replace cement and are effective in enhancing some physical and mechanical properties of the cementitious matrix. ยท A model for predicting autogeneous shrinkage of concrete from paste was proposed based on a concept of 2-phase material which are paste and aggregate phases. Test on mortars and prepacked concrete were conducted to verify the proposed model. The proposed model was found to be effective in predicting the autogeneous shrinkage of a paste-aggregate composite system. |
| Year | 1993 |
| Type | Thesis |
| School | School of Engineering and Technology (SET) |
| Department | Department of Civil and Infrastucture Engineering (DCIE) |
| Academic Program/FoS | Structural Engineering (STE) /Former Name = Structural Engineering and Construction (ST) |
| Chairperson(s) | Pichai Nimityongskul ;Sommuk Tangtermsirikul; |
| Examination Committee(s) | Karasudhi, Pisidhi ;Aoyagi, Yukio |
| Scholarship Donor(s) | Government of Switzerland; |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 1993 |