This report will generally discuss the progress and basic understanding on the selected Final Year Project (FYP) title, which is Effects of Curing Regime and Binders on Polymer Concrete. Therefore, it is essential to introduce new technologies and practices for alternative cements in order to limit the increasing C02 emissions caused by the increased production of Portland cement and to solve the serious problems of disposal of by-product materials such as fly ash, silica fume and rice husk ash. This research was carried out to determine the optimum proportion of polymer concrete mix comprising fly ash, MIRHA and silica fume.
This research used low calcium fly ash (ASTM Class F), MIRHA and silica as source materials in the production of polymer concrete. As a result of this research, it can be concluded that fly ash, MIRHA and silica together with alkaline solution (sodium hydroxide, NaOH and sodium silicate, NazSi~) can be a good substitute for cement in concrete, and curing by external exposure is the best curing regime for polymer concrete cast in situ. Figure 4.6: Compressive strength of fly ash-MIRHA with hot curing 33 Figure 4.7: Compressive strength of silica fly ash with ambient 34.
INTRODUCTION
BACKGROUND STUDY
The last term in equation 2 reveals that water is released during the chemical reaction that occurs in the formation of geopolymers. Water in the geopolymer mixture does not participate in the chemical reaction, as water ensures the usability of the mixture during handling. This is in contrast to the chemical reaction of water in the Portland cement concrete mix during the hydration process (Davidovits, 1994; Van Jaarsvels et al, 1997).
The starting materials for alumina-silicate geopolymers should be rich in silicon (Si) and aluminum (Al). Alternatively, by-product materials such as fly ash, silica fume, slag, rice husk ash, red mud, etc. could be used as source materials (Davidovits, 1994; Van Jaarsvels et al., 1997). The source materials for making geopolymers should be selected depending on factors such as the type of application, availability and specific end-user demand, and cost.
PROBLEM STATEMENT
OBJECTIVES
SCOPE OF STUDY
CHAPTER2
LITERATURE REVIEW
BY-PRODUCT MATERIALS USED IN CONCRETE MANUFACTURING
1985) stated that dry curing regimes have a greater effect on the strength of silica fume compared to Portland cement. Remezaniapour and Malhotra (1995) reported that the compressive strength of concrete with silica fume will decrease by 28% due to dry curing. They reported that moisture curing had no significant effect on the sample containing silica fume although moisture curing had a significant effect on the control concrete.
There is inconsistency between the studies regarding the influence of the curing regime on concrete containing silica vapour. Therefore, more research is needed on the effect of different curing regimes on silica vapor concrete or concrete incorporating other pozzolanic materials, such as fly ash and MIRRA. Rice husk ash has been proven to contain amorphous silica that can be used to enhance the effects of durability in concrete (Spire et. al. reported that rice husks are used to produce lightweight concrete. It can improve the tensile strength of concrete.
CEMENT REPLACEMENT MATERIALS .1 Fly Ash
- Rice Husk Ash
Regarding the influence on flexural strength, Khedr and Abou-Zeid (1994) found that silica concrete increases the flexural strength up to 20% to 33% by 15% and 20%. Regarding effects of tensile strength, Hooton (1993) reported that the tensile strength of concrete with 15% and 20% silica fume showed a reduction in strength of 9.7% and 21%, respectively. Furthermore, the addition of silica fume reduces the splitting tensile strength of concrete at the age of 91 days.
The use of silica fume in concrete increases the concrete's resistance to acid and sulfate attack. Moreover, it improves the durability of concrete by reducing the porosity and permeability of the cement paste matrix (Erdogan, 2003; Akoz et. al. In addition, it makes the concrete more resistant to abrasive forces and reduces the expansion generated by the expansion of alkaline aggregate (Mehta, 1985 ).
CHAPTER3
- MATERIALS SELECTION
- Fly Ash
- Microwave Incinerated Rice Husk Ash (MlRHA) .1 Burning procedure
- Alkaline Solution
- Aggregate
- Sugar
- Water
- CONCRETE MIXING, CASTING AND COMPACTING
- CURING OF POLYMERIC CONCRETE
- CONCRETE TESTING
- Slump Test
- Compressive Strength Test
- Flexural Strength Test
- Indirect Tensile Strength Test
The alkaline solutions used in this study are sodium hydroxide (NaOH) and sodium silicate (Na2SiO3). Sugar was used as a retarder in this study. It was adopted from Pedis, Malaysia. Sugar has been added to slow down the curing time of polymer concrete. This is because impurities in water can interfere with the setting of the cement, negatively affect the strength of the concrete or cause surface staining (Neville, 1995).
The machine mixing procedure that was used in this research was carried out to set the mixing standard for polymer concrete. After mixing, the fresh polymer concrete mixture was mixed by hand to ensure homogeneity of the polymer concrete. Three types of curing regimes that were used in this research are heat gun, ambient and external exposure curing until they are taken for testing.
In ambient curing, the concrete sample was placed in a shaded area, which was protected from rain and sunlight, but still receives temperature from the outside environment as illustrated in Figure 3.14. The chamber allows sunlight to penetrate while protecting the samples from rain as shown in Figure 3.15. Before performing the drop test, the inner surface of the cone and its base should be washed to reduce the influence of surface friction on the drop result.
After the last layer has been pressed, the top surface is struck by the rotary motion of the press rod. The decrease in the height of the dropped concrete is called slump and is measured to the nearest 5 mm. The compressive strength of concrete was determined by performing compressive strength according to BS EN using compression testing machine.
The flexural strength of concrete is determined by carrying out the BS EN flexural strength test using a Compressive Testing Machine. The maximum theoretical tensile stress reached in the bottom fiber of the test beam is known as the modulus of rupture. The tensile strength of polymer concrete incorporating fly ash, MIRHA and silica fume was measured by performing cylinder split test as per BS EN using Compressive Testing Machine.
CBAPTER4
Properties of Fresh Concrete
From the result obtained, the drop height obtained from the research is high which are in the range of I 60mm to 240mm. Therefore, the workability of fresh polymer concrete decreased with increasing percentage of MIRHA content in polymer concrete.
Properties of Hardened Concrete
- Tensile Strength Test
- Flexural Strength Test
Flexural strength test was conducted to determine the impact of MIRHA and silica fume on flexural strength of concrete sample at the age of 28 days. Polymeric concrete incorporating silica fumes in hot gunny curing gives the highest flexural strength while ambient curing gives the highest flexural strength on polymeric concrete containing MIRHA. Based on ACI comments, tensile strength in bending is 10-15 % of compressive strength which is slightly better for polymeric concrete.
Flexural strength values for polymer concrete containing silica fume and MIRHA are illustrated in Tables 4.3 and 4.4. Compressive strength tests have been conducted to analyze the effect of silica fume and MIRRA on the strength of polymer concrete. Since fly ash has already reacted with alkaline solution, it took time for polymer concrete to react with MIRRA and silica fume.
In terms of compressive strength, 7% replacement of fly ash with silica fume is the optimum amount for hot gun firing, 3% is the optimum amount for ambient firing. Thus, 5% replacement of fly ash with MIRRA is the optimal amount for hot and ambient firing. Under low temperature conditions, as performed by hot gun annealing and ambient curing, the rate of polymer reaction is slow.
Therefore, the mixed parent material could improve the strength of concrete with a lower reaction rate, as shown in Figure 4.7 and Figure 4.8, respectively. However, the addition of silica and MIRHA during exposure curing does not increase the strength of polymer concrete.
CHAPTERS
CONCLUSION AND RECOMMENDATION
CONCLUSION
External exposure to curing gives the highest compressive strength for polymer concrete containing fly ash-silica and MIRHA of 48.70 MPa. For polymer concrete containing fly ash-MIRHA, the compressive strength in hot curing is in the range of 11.50 to 19.01 MPa, in atmospheric curing in the compressive strength range from 16.75 to 24.08 MPa, and in external curing in the compressive strength range from 27.58 to 48.70 MPa. . The tensile strength of polymer concrete containing fly ash-silica when curing in hot gas is in the range of 1.35 to 1.77 MPa, when curing in the environment the compressive strength is in the range of 0.95 to 2.17 MPa, when exposed to external conditions, the compressive strength ranges from 1.31 to 2.45 MPa.
70 MPa, in ambient curing the compressive strength range from 0.95 to 1.89 MPa, while in external exposure curing the compressive strength range from 1.29-2.45 MPa. The tensile strength of polymer concrete is a percentage of its compressive strength which is similar to OPC concrete. Flexural strength of polymer concrete incorporating fly ash-silica fume in hot gun hardening ranges from 4.91 to 8.35 MPa, in ambient hardening, compressive strength range from 3.36 to 6, 58 MPa, while in external curing, the compressive strength range from 4.53 to 7.91 MPa from 4.53 to 7.91 MPa.
In the polymer concrete incorporating fly ash-MIRHA in the hot curing of the stone, the compressive strength varies from 3.25 to 5.44 MPa, in the ambient hardening, the compressive strength.
RECOMMENDATION
CHAPTER6 ECONOMIC BENEFITS
COST OF PROJECT
Chemical attack of low water cement ratio concretes containing latex or silica fume as admixture. The role of fly ash in sustainable development, Forum Proceedings, EHD Architecture and the Pacific Energy Center;. http://www.buildinggreen.com/features/flyashlmehta.html). A Reassessment of the International Conference on the Use of Fly Ash, Silica Fume, Slag and Natural Pozzolans in Concrete.
Effect of curing on the compressive strength, resistance to chloride ion penetration and porosity of concrete containing slag, fly ash or silica fume. 34;Low-Calcium Fly Ash-Based Geopolymer Concrete" Chapter 26 in Concrete Construction Engineering Handbook, Editor-in-Chief: E.G. Rysskil in Lightweight Mortars, In: Second International Symposium on Structural Lightweight Aggregate Concrete, Kristiansand, Norway, June 18-22, 2000: p.
APPENDIX A
Million
APPENDIXB
TENSILE STRENTH TEST RESULT
