Influence of rice husk ash on volume changes and compressive strengths of fly ash - Portland cement mortar | |
| Author | Bhanu Raksasataya |
| Call Number | AIT Thesis no.ST-90-13 |
| Subject(s) | Portland cement--Additives Mortar--Additives Fly ash |
| 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 was conducted to observe the behavior of fly ash collected from Mae- Moh Lignite Power Plant as a replacement for Portland cement and also investigate the effect of rice husk ash as an ingredient in blended fly ash- Portland cement. Among the properties investigated are chemical composition , physical properties, compressive strength , early volume change and long term dimensional change, the main parameter considered in the experimental program is the percentage of fly ash and rice husk ash replacement. Test results showed that the compositions of this fly ash fluctuated over a wide range , and resulted in low quality pozzolan for u sing as an ingredient in Portland cement. The strength of fly ash cement mortar was lower than that of corresponding control mortar. It can mentioned that the compressive strength of Mae-Moh fly ash cement mortar is controlled not only by its chemical compositions but also the degree of fineness. For the compressive strength of RHA cement mortar, at early ages, was lower than that of the control mortar. However , at later ages, up to 90 days the strength of RHA cement mortar was substaintially higher. The combination of fly ash ,having high Sulphur trioxide and calcium oxide content , and Portland cement produced very high expansion. The expansion occurred in higher rate during the first 5- 48 hrs after casting , and subsequently become infinitesimal. For long term curing, after 30 days, the expansion of fly ash cement mortars kept in moist condition created very small expansion value while the specimen kept in dried condition exhibited drying shrinkage in the same way as Portland cement. The combination of fly ash , RHA and Portland cement resulted in lower expansion compared with blended fly ash Portland cement, and also reduced drying shrinkage. Furthermore, with proper combination , t he compressive strength was considerably improved. It was recommended that fly ash together with RHA can be used as a replacement for Portland cement up to 50 % while its strength and its volume changes still be about the same as those of the normal Portland cement. |
| Year | 1990 |
| Type | Thesis |
| School | School of Engineering and Technology (SET) |
| Department | Other Field of Studies (No Department) |
| Academic Program/FoS | Structural Engineering (STE) /Former Name = Structural Engineering and Construction (ST) |
| Chairperson(s) | Pichai Nimityongskul; |
| Examination Committee(s) | Karasudhi, Pisidhi ;Worsak Kanok-Nukulchai |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 1990 |