จำนวน Repository ( 13 )
การตรวจสอบความเป็นสารปอซโซลานของเถ้าแกลบผสมเถ้าลอยโดยวิธีการบ่มเร่งกำลัง
This paper presents the investigation of pozzolanic reaction of rice husk ash blended with fly ash by accelerated curing. The compressive strength of cement paste containing rice husk ash blended with fly ash at 30% by weight of cementitious material (PBA-30) was studied. The temperature curing at 60 70 and 80oC were parameter of test in order to determine the suitable temperature and curing period on strength development of cement paste. The ratio of rice husk ash to fly ash was 1:1 by weight and the ratio of water-to-binder (w/b) was 0.38. The test results found that the accelerated curing of PBA-30 at temperature of 60oC for 5 10 and 45 hours had comparable compressive strength to PBA-30 with normal curing at the age of 37 and 28 days respectively. As a result of accelerated curing the calcium silicate (CS) which effect on strength development of cement paste was increased. According to the X-ray diffraction analysis the calcium silicate content in cement paste was comparable. Therefore it can be use accelerated curing to investigate the poozolanic reaction of rice husk ash blended with fly ash within 48 hours.
การพัฒนาเถ้าแกลบและเถ้าถ่านหินเพื่อใช้แทนที่ปูนซีเมนต์ปอร์ตแลนด์ในงานคอนกรีตกำลังสูง
This research presents a study of the use of classified fly ash and ground rice husk ash as a pozzolanic material in producing high-strength concrete. Portland cement (CT) is partially replaced with classified fly ash and ground rice husk ash by weight of the cementitious materials. Compressive strength porosity and chloride penetration were investigated. The results show that the compressive strength resistance to chloride and low porosity of high-strength concrete improves substantially with partial replacement of Portland cement with fly ash and rice husk ash.
การสังเคราะห์ซิลิกาจากขี้เถาแกลบเพื่อมาประยุกต์ใช้ในการทำแก้วคริสตัลสี
The aim of this work was to synthesis the glass crystals by using silica from rice husk ash (RHA) as a raw material. First rice husk was synthesis by heated at various temperatures between 1000-1200 °C and then silica which was heated at the first step was used to be the raw materials for glass crystal. From the result shows that RHA with heated at 1000-1200 °C could be use for silica to synthesis crystals glass. X-ray Diffraction pattern demonstrated that all of condition to heat RHA showed the same results Cristoballite Tridamite are the phase formation appeared all of materials. The crystal glass show blue colour. The optimum condition with show the highest density and density value were obtain with the sample of heated RHA at 1000 °C
Effect of rice husk ash blended with fly Ash on mechanical properties of concrete
This research aimed to investigate the effect of rice husk ash blended with fly ash on mechanical properties of concrete including compressive and flexural strengths. The studied parameter was the replacement percentages of cement by rice husk ash blended with fly ash at 0 30 and 50 by weight of cementitious materials. The constant ratio of rice husk ash to fly ash of 1:1 by weight was used in this study. The test results showed that the strength of concrete decreased while the replacement percentages of rice husk ash blended fly ash increased. The compressive strength at the age of 7 days of concrete containing rice husk ash blended with fly ash was lower than the control concrete but concrete containing rice husk ash and fly ash at 30% by weight of cementitious materials had comparable compressive and flexural strengths at the age of 28 days to the control concrete. As for the results the mechanical properties of concrete containing rice husk ash blended with fly ash at 30% by weight of cementitious materials were comparable to the control concrete.
การพัฒนาวัสดุจีโอโพลีเมอร์จากเถ้าแกลบและเถ้าชานอ้อย
This research studies the potential for using waste ash from industrial and agricultural by–products as a geopolymer material. This paper presents a study of the resistance to chloride penetration and resistance to sulfuric acid of geopolymer mortar containing ground rice husk ash (RA) and ground bagasse ash (BA). Geopolymer mortars with constant liquid to ash ratio and similar flow were used for the tests. Compressive strength porosity chloride penetration test Rapid migration test of chloride depth chloride ion diffusion coefficient immersion test of chloride depth and weight loss with impressed sulfuric acid were investigated. Test results show that the workable flow of geopolymer mortar was in the range of 110–115% and was dependent on the ratio by mass of sodium silicate to NaOH and the concentration of NaOH. Extra water was used to improve the workabililty. In case of rice husk ash geopolymer mortar the geopolymer mortars with high strengths were obtained with concentration of NaOH of 15M with the sodium silicate to NaOH ratio by weight of 2.5. However the bagasee ash geopolymer mortars with high strengths were obtained with concentration of NaOH of 10M with the sodium silicate to NaOH ratio by weight of 2.5. The use of rice husk ash and bagasse ash produces geopolymer mixes with good strength and resistance to acid and chloride penetration. The resistance to acid and chloride penetration is higher with an increase in the sodium silicate to NaOH ratio by weight of 2.5.