ABSTRACT
The geopolymer of fly ash (FA) and rice husk ash (RHA) was prepared. The burning temperature of rice husk, the RHA fineness and the ratio of FA to RHA were studied. The density and strength of the geopolymer mortars with RHA/FA mass ratios of 0/100, 20/80, 40/60, and 60/40 were tested. The geopolymers were activated with sodium hydroxide (NaOH), sodium silicate, and heat. It is revealed that the optimum burning temperature of RHA for making FA-RHA geopolymer is 690°C. The as-received FA and the ground RHA with 1%-5% retained on No.325 sieve are suitable source materials for making geopolymer, and the obtained compressive strengths are between 12.5-56.0 MPa and are dependent on the ratio of FA/RHA, the RHA fineness, and the ratio of sodium silicate to NaOH. Relatively high strength FA-RHA geopolymer mortars are obtained using a sodium silicate/NaOH mass ratio of 4.0, delay time before subjecting the samples to heat for 1 h, and heat curing at 60°C for 48 h
CHAPTER ONE
1.0 INTRODUCTION
As worldwide awareness and concern over global climate change, increases, the greenhouse gas intensiveness of Portland cement manufacture is attracting scrutiny. Available replacement geopolymer cement, is currently receiving increased attention in academic and industrial communities for its ability to serve as a binder in structural concrete application. Geopolymers are formed when aluminosilicates dissolve in a strong solution, recognize and precipitate on a hardened state. The term “geopolymer” was coined by Prof. Joseph Davidovits in the year 1970s following research into inorganic-polymer technologies for industrial application and applied to a class of solid materials synthesized by the reaction of an alumino-silicate powder with a solution.
These materials were originally developed as a fire-resistant alternative to organic thermosetting polymers following a series of fires in Europe and products based on this initial work have since found application as coating for fire protection for cruise ships, as a resin in high temperature carbon-fibre composites in thermal protection of wooden structure as a heat-resistant adhesive as a monolithic refractory and in various other niche application. However, as can be seen from brief perusal of geopolymer, the primary application for geopolymer binders has since shifted to uses in construction, transportation, offshore and infrastructure application.
1.1 AIM:
i. The study is aimed at evaluating the performance of geopolymer cement from rice husk ash and coal ash.
ii. To complement, supplement conventional Portland cement as binder.
OBJECTIVE
The objectives of the study include:
(i) Carry out a performance test, carry out analysis of result.
(ii) Draw conclusion based on the test results.
1.2 SCOPE AND LIMITATION
– The scope of this project is to source relevant raw materials.
– Subject of the raw materials to production technique.
– Carry out actual productions of geopolymer.
– Carry out test of performance or other test.
– Analyse test, results and draw conclusion
LIMITATION
The study would be limited by such factor as constrain arising from lack of information, fund and research materials.
1.3 SIGNIFICANCE
The project would have the following significances:
– Improve the student knowledge of geopolymer cement and related materials
– Provides support for existing materials.
– Provides alternative to existing materials.
– Boost the economy of the local area.
– Justify the shift towards local content.
– Contribute to research work as a reference materials for further research
1.4 JUSTIFICATION
The availability of the raw materials for the production
The affordability of the cost of the projects.
The availability of human resources.
The accessibility of the supervising team are among the justification for carrying out this project.