จำนวน Repository ( 15 )
กำลังและความต้านทานการกัดกร่อนของมอร์ต้าร์ที่ใช้วัสดุประสานกระตุ้นด้วยด่างจากเถ้าถ่านหินแคลเซียมสูง
The aim of this study is developed of alkali activated high calcium fly ash to use as cementitious material to replace Portland cement. The mixture of mortar made from fly ash and sodium hydroxide solution (NaOH) was used to activate strength at concentrations of 2 4 6 and 8 molars. Superplasticizer was used to control the flow of mortar in the rage of 105 – 110. The compressive strength of mortar was determined at 7 28 45 and 60 days. The acid resistance of mortars due to sulfuric at a concentration of 3% were also investigated. The results showed the mortar made from high calcium fly ash with sodium hydroxide of 6 molar obtained the highest compressive strength which could be developed compressive strength up to 189 ksc at 60 days. For the acid resistance of mortar it was found that the of use 6 molar of NaOH activated high calcium fly ash binder had the least weight loss due to sulfuric acid attack.
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.
การพัฒนาคุณสมบัติของต้นแบบแผ่นมวลเบาจากเศษใยยางพาราและเถ้าไม้ยางพาราสำหรับประยุกต์ในระดับภาคสนาม
The development of lightweight flat sheet prototype from para rubber leaves and para para rubber wood fly ash for field work application can offer an alternative method of adding value to agricultural wastes and help to conserve the environment with green products. The natural fiber especially agricultural waste fiber is an encouraging prospect. Natural fiber composites have been used for building applications. The aim of this research was to investigate the potential use of para wood ash to producing a cement composite as an environmentally material. Material. The cement paste with 5-2 % weight of para wood ash. The specimens were cured at 25± 2 oc for 24 hours. The properties of cement composites mixed with different proportions of para wood ash were compared with Ordinary Portland Cement (OPC). In addition the morphology of para wood ash was examined by using scanning electron microscope. The density increased with the increase in the percentage of para rubber leaves from 1% 2% 4% and 6%. The finding is attributable to the enhanced packing density by the fine para wood ash particles size was found 5-10 um.Moreover para wood ash particles could arrange to fill the inter-particle voids in cement pastes which resulting to increase the compressive strength of cement paste. Consequently para wood ashes could incorporate in the construction materials to enhance the mechanical properties and durability performance of the cement composites
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.
การรับแรงกระแทกของคอนกรีตผสมดินขาวและเถ้าลอย
This research to study the possibility of material pozzolan as binder by replacment cement by fly ash (FA) and meta kaolin (MK) some for testing compressive strength flexural strength and impact strength of concrete vary the ratio of water to binder (w / b) of 0.40 and 0.45 and the amount of fly ash to replace cement some 15 % 30 % MK and 35% for 10% 15% and 20% by weight of cement. The sample consisted of a cylinder diameter of 10 x 20 cm beam sizes 10 x 10 x 40 cm and 4 x 4 x 16 cm from the test results showed that the concrete samples at 28 days and w/ b of 0.40 to greater than 0.45 all mixed. the compressive strength by replacing cement with FA increase up to 30 % compression of 382 ksc higher than the 20 percent replace by MK were equal to 354 ksc and 32.48 ksc compared to replace cement with FA 15 % is equal to 31 ksc 30% were equal to 30 ksc and 45% were equal to 23.85 ksc while the MK was replaced by 10% were equal to 40.10 ksc higher than to 15% and 20% respectively. The control sample was replaced with MK by 10% is equal to 111 joules maximum replaced by fly ash more than 30% were equal to 110 joules and MK were 15% fly ash 15 and 45 percent respectively.