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 หัวเรื่อง:ไม่มีชื่อไทย (ชื่ออังกฤษ : Effect of Cement Replacement by Rice Husk Ash on Soft Soil Stabilization) ผู้เขียน: Naphol Yoobanpot, Pitthaya Jamsawang สื่อสิ่งพิมพ์:pdf AbstractThe characteristics of soft soil improvement using cement and rice husk ash were studied. Compressive strength testing of stabilized soil was investigated with various curing times of 3, 7, 14 and 28 d. The correlation between strength development and reaction products was investigated using X-ray diffraction analysis after the strength tests and changes in the stabilized soil structure were investigated using scanning electron microscopy. The results revealed that the soil strength increased when the soil was stabilized with cement and partial replacement of cement with rice husk ash. The results indicated that 30% rice husk ash was the appropriate content for partial cement replacement to produce a stabilized soil strength of 424, 722, 915 and 1,126 kPa at 3, 7, 14 and 28 d curing, respectively. It was also found that the increase in the strength of the stabilized soil was relative to the formation of major reaction products such as calcium silicate hydrate. |
หัวเรื่อง:ไม่มีชื่อไทย (ชื่ออังกฤษ : Stabilization of Soft Clay Using Waste-Based Cement) ผู้เขียน: ดร.ศุภกิจ นนทนานันท์, รองศาสตราจารย์ , Naphol Yoobanpot สื่อสิ่งพิมพ์:pdf AbstractThis research focused on the potential utilization of waste-based cement (WBC) as a stabilizer to improve the compressive strength of soft clay and also aimed to verify the hardening effects of WBC compared to ordinary Portland cement (OPC). Evaluation of hardening effects was performed based on the compressive strength test and by means of physicochemical tests. The experimental results revealed that the unconfi ned compressive strengths of soil mixes can be improved by stabilizing with WBC to a similar extent to that achieved using OPC. The improvement in strength was due to the enhancement of hydration producing calcium silicate hydrate and calcium aluminate hydrate. |
หัวเรื่อง:ไม่มีชื่อไทย (ชื่ออังกฤษ : Strength Development of Soft Marine Clay Stabilized with Cement and Fly Ash) ผู้เขียน:ดร.ศุภกิจ นนทนานันท์, รองศาสตราจารย์, สานุพงษ์ บุญยงค์, Thakol Yoobanpot, ดร.ก่อโชค จันทวรางกูร, รองศาสตราจารย์ สื่อสิ่งพิมพ์:pdf AbstractThis study combined the concepts of chemical ground improvement technique with environmental geotechnics for improvement of a soft marine clay. The objectives were to study strength development of the cement stabilized soils and to illustrate potential use of the fly ash obtained from a vegetable oil factory as a cement replacement material. Attempt was also made in order to elucidate contributions of fly ash as well as reaction products to the development of strengths. Hardening effects were investigated through unconfined compressive strength. In order to elucidate strength development and its correlations to reaction products, X-ray diffraction analysis (XRD) were also performed after strength tests. Based on the experimental results, strengths were markedly increased when mixed with OPC and OPC with 10% fly ash replacement. Soil mixtures with fly ash content higher than 20% exhibited relatively lower strengths at short term, however, steady gains in strength could be observed at long term. In addition, correlations between reduction on strength and fly ash content were proposed and prediction on strengths for the predetermined fly ash content could be made. It could be concluded that strength development was attributed to the hydration and pozzolanic reactions. It was also found that increase in compressive strength was directly proportional to amounts of the major reaction product such as calcium silicate hydrate (CSH). |
หัวเรื่อง:ไม่มีชื่อไทย (ชื่ออังกฤษ : Influence of Fineness of Cement Produced from Industrial Wastes on Strength of Mortar) ผู้เขียน:ดร.ศุภกิจ นนทนานันท์, รองศาสตราจารย์, Naphol Yoobanpot, นางดวงฤดี ฉายสุวรรณ, รองศาสตราจารย์ , 520221 สื่อสิ่งพิมพ์:pdf AbstractThe effect of the fineness of cement produced from waste-based clinker on mortar strength was studied. Combinations of wastes—namely, ark shell, waste limestone powder and water supply sludge—with the addition of hydrated lime were prepared with an appropriate mix proportion for the clinkerization process to produce cementitious material. Clinkers were ground in order to obtain a target fineness ranging from 2,000 to 3,500 cm2/g and then blended with 5% gypsum by weight to produce a waste-based cement similar to an Ordinary Portland Cement type I (OPC). The chemical and physical properties of the waste-based cement were investigated and compared with those of OPC. The results revealed that the mortar strengths of the waste-based cement increased with curing time but were relatively lower than those of OPC. Cracking and swelling could be observed in mortars produced from wastebased cement having relatively low fineness. The negative effects could be eliminated when cement fineness was increased, resulting in markedly increased strengths. Expansion behavior due to the reaction of free lime and the formation of ettringite in cement pastes was observed and its implications discussed. |
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