Influence of different types of supplementary cementing materials on the durability of mortars | |
| Author | Kovit Visessompak |
| Call Number | AIT Thesis no. ST-97-9 |
| Subject(s) | Mortar--Testing Concrete--Permeability Mortar--Testing Concrete--Permeability |
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering. |
| Publisher | Asian Institute of Technology |
| Series Statement | Thesis ; no. ST-97-9 |
| Abstract | The influence of different types of supplementary cementing materials on the durability of mortar was investigated in this study. The emphasis of this research was placed on the durability expressed in term of the permeability of mortar. To achieve these objectives, experiments were conducted by measuring the weight of water penetrating into the mortar specimens by applying a constant pressure over a period of time by using a specially designed apparatus. There were three types of pozzolans investigated in this study namely fly ash, rice husk ash and metakaolin. The content of pozzolans used as cement replacement was varied at 0%, 20%, 30% and 40% by weight of cementitious materials. The resistance of mortars to hydrochloric acid and sulphuric acid was also investigated. Moreover, the compressive strength of mortars, the workability of fresh mortars in term of the flow value and chemical and physical properties of pozzolans used in this study were determined. The test results indicated that partial replacement of ordinary Portland cement (OPC) by metakaolin significantly improved the impermeability of mortars. The magnitude of permeability of metakaolin-OPC mortars was found to be about one-half of OPC mortars. The permeability also decreased with the increase in metakaolin content. However, replacing OPC by fly ash or rice husk ash did not give the same results. When the percentage replacements of fly ash and rice husk ash increased, the impermeability of mortars was considerably reduced. The resistance against sulphuric acid of fly ash-OPC, rice husk ash-OPC and metakaolin-OPC mortars were significantly higher than that of OPC mortars. And metakaolin-OPC mortars possessed the best resistance among these three types of pozzolan-OPC mortars. For the resistance against hydrochloric acid, fly ash-OPC and rice husk ash-OPC mortars showed similar results with that of OPC mortars whereas metakaolin-OPC mortars possessed the ยท poorest resistance. The compressive strengths at 28 days of metakaolin-OPC were found to be slightly higher than that of OPC mortars. However, the strengths at 60 days of metakaolinOPC mortars for 20% and 30% replacements were slightly lower when compared with that of OPC mortars. Replacement OPC by fly ash or rice husk ash resulted in a reduction in the compressive strengths of mortars for all cases except 20% fly ash replacement. The relationship between the compressive strengths and the permeability of mortars indicated that the higher the permeability, the lower the compressive strength. This phenomenon was also observed in other researches. |
| Year | 1997 |
| Corresponding Series Added Entry | Asian Institute of Technology. Thesis ; no. ST-97-9 |
| 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) | Pichai Nimityongskul;Pichai Nimityongskul; |
| Examination Committee(s) | Niwa, Junichiro;Ogunlana, Stephen O; |
| Degree | Thesis (M. Eng.) - Asian Institute of Technology, 1997 |