Study on the Production of Eco-friendly Construction Brick Based on Geopolymerization
| Autor: | Trong-Phuoc Huynh, 黄重福 |
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| Rok vydání: | 2014 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 102 With the objectives of reducing the negative impacts on environment and utilizing of waste materials, the possibility of producing eco-friendly construction bricks by using fly ash (FA) and rice husk ash (RHA) with applying geopolymerization combined with Densified mixture design algorithm (DMDA) method was investigated in the present study. There are two main stages of experimental programs, which are named as geopolymer paste development and eco-friendly construction bricks production, in this investigation. It was noticed that all geopolymer paste specimens and brick samples were kept in the same curing conditions for these stages. In the first stage, geopolymer paste specimens of 50 × 50 × 50 mm in size were prepared. The effect of various parameters such as liquid-to-solid (L/S) ratio, sodium hydroxide (NaOH) concentration, sodium silicate (Na2SiO3) dosage and RHA amount on the compressive strength of the specimens at different ages was investigated in this stage. Whereas, in the second stage, eco-friendly construction bricks in size of 220 × 105 × 60 mm were prepared for the tests of dimensions and visible defects, compressive strength, flexural strength, water absorption, bulk density and void volume to evaluate the hardened properties of brick samples. In this stage, especially, unground rice husk ash (URHA) was used as a partial replacement of natural sand in the mixtures and forming pressure was applied to form the solid bricks in the steel mold. From the test results of geopolymer paste specimens, the optimum conditions were found to be that the L/S ratio was 0.37, NaOH concentration was 10M, RHA amount was 40% weight of binder and compressive strength was increased corresponding to the increase in Na2SiO3 dosage from 10% to 25%. By following these conditions for the bricks production stage, the compressive strength, flexural strength and water absorption of the bricks without URHA added were respectively in range of 29.31 – 31.46 MPa, 5.19 – 6.91 MPa and 8.83 – 10.11% and the other properties of the bricks were well conformed to Vietnamese Standard (TCVN 1541:1998). It was found that the addition of URHA in the mixture caused the decrease in mechanical strength as well as in other properties of the bricks. In summary, the test results clearly indicated that all brick samples had very good mechanical properties and durable performance that were much better than the requirements of TCVN 1451:1998. It was definitively proved many possible applications of FA and RHA in the production of eco-friendly construction bricks. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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