24 research outputs found
Use of disposed waste ash from landfills to replace Portland cement
In this study, waste ash was utilized as a pozzolanic material in blended Portland cement in order to reduce negative environmental effects and landfill volume required to dispose of waste ash.In this study, waste ash was utilized as a pozzolanic material in blended Portland cement in order to reduce negative environmental effects and landfill volume required to dispose of waste ash. The influence of waste ash, namely palm oil fuel ash, rice husk ash and fly ash on compressive strength and sulfate resistance in mortar were studied and evaluated by some accelerated short–term techniques in sodium sulfate solutions. Ordinary Portland cement (OPC) was partially replaced with ground palm oil fuel ash (POA), ground rice husk ash (RHA) and classified fly ash (FA). Single pozzolan and a blend of equal weight portions of POA, RHA and FA were also used. The resistance to sulfate attack of mortar improves substantially with partial replacement of OPC with POA, RHA and FA. The use of a blend of equal weight portions of FA and POA or RHA produced mixes with good strength and resistance to sulfate attack. POA, RHA and FA have a high potential to be used as a pozzolanic material
Strength, porosity and corrosion resistance of ternary blend Portland cement, rice husk ash and fly ash mortar
This paper presents a study of the strength, porosity and corrosion resistance of mortars made with ternary blends of ordinary Portland cement (OPC), ground rice husk ash (RHA) and classified fly ash (fine fly ash, FA). Compressive strength, porosity and accelerated corrosion with impressed voltage (ACTIV) were tested.This paper presents a study of the strength, porosity and corrosion resistance of mortars made with ternary blends of ordinary Portland cement (OPC), ground rice husk ash (RHA) and classified fly ash (fine fly ash, FA). Compressive strength, porosity and accelerated corrosion with impressed voltage (ACTIV) were tested. The results show that the use of ternary blend of OPC, RHA and FA produces mortars with improved strengths at the low replacement level with RHA and FA and at the later age in comparison to that of OPC mortar. The porosity of mortar containing pozzolan reduces with the low replacement level of up to 20% of pozzolan, but increases with the 40% replacement level. The chloride induced corrosion resistance of mortar as measured by ACTIV is, however, significantly improved with the use of both single pozzolan and the ternary blend OPC, RHA and FA. The corrosion resistance of ternary blend mortar is higher than that of mortar containing single pozzolan. The use of ternary blend OPC, RHA and FA is very effective in enhancing chloride induced corrosion of mortar
Use of waste ash from various by-product materials in increasing the durability of mortar
This paper presents a study on the strength and corrosion resistance of mortars made with binary blends of ordinary Portland cement (OPC) and ground rice husk ash (RHA) or ground palm oil fuel ash (POA).This paper presents a study on the strength and corrosion resistance of mortars made with binary blends of ordinary Portland cement (OPC) and ground rice husk ash (RHA) or ground palm oil fuel ash (POA). The mortar mixtures were made with Portland cement Type I containing 0-40% RHA and POA. RHA and POA with 1-3% by weight retained on a sieve No.325 were used. The water to binder ratio was kept constant at 0.5 and the flow of mortar was maintained at 110±5% with the aid of superplasticizer (SP). Scanning electron microscopy (SEM) was used for analysis. The compressive strength, chloride penetration and corrosion resistance of the mortar were determined. The results show that strength as well as the resistance of mortar to chloride and corrosion can be improved by blending with RHA and POA. Thus, RHA and POA have a high potential to be used as a good pozzolanic material
Strength and chloride resistance of blended Portland cement mortar containing palm oil fuel ash and fly ash
This paper presented a study on the strength and chloride resistance of mortars made with ternary blends of ordinary Portland cement (OPC), ground palm oil fuel ash (POA), and classified fly ash (FA). The mortar mixtures were made with Portland cement type I containing 0-40wt% FA and POA. FA and POA with 1wt%-3wt% retained on a sieve No.325 were used. The compressive strength and rapid chloride penetration depth of mortars were determined.This paper presented a study on the strength and chloride resistance of mortars made with ternary blends of ordinary Portland cement (OPC), ground palm oil fuel ash (POA), and classified fly ash (FA). The mortar mixtures were made with Portland cement type I containing 0-40wt% FA and POA. FA and POA with 1wt%-3wt% retained on a sieve No.325 were used. The compressive strength and rapid chloride penetration depth of mortars were determined. The results reveal that the use of ternary blended cements produces good strength mortars. The use of the blend of FA and POA also produces high strength mortars and excellent resistance to chloride penetration owing to the synergic effect of FA and POA. A mathematical analysis and two-parameter polynomial model were presented to predict the compressive strength. The mathematical model correlated well with the experimental results. The computer 3-D graphics of strength of the ternary blended mortars were also constructed and could be used to aid the understanding and the proportioning of the blended system
An Experimental investigation of the carbonation of blended portland cement palm oil fuel ash mortar in an indoor environment
This research, palm oil fuel ash was utilized as a pozzolanic material in blended Portland cement mortar. The mortar was tested on the normal compressive strength and the negative effect of carbonation in indoor environment using the accelerated carbonation test of 5% CO2 in 50% relative humidity. Three palm oil fuel ash fractions of different fineness, viz., coarse original palm oil fuel ash (CPOA), medium palm oil fuel ash (MPOA) and fine palm oil fuel ash (FPOA) were used for the study. Ordinary Portland cement (OPC) was partially replaced by these palm oil fuel ashes at the dosages of 20% and 40% by weight of binder.In this research, palm oil fuel ash was utilized as a pozzolanic material in blended Portland cement mortar. The mortar was tested on the normal compressive strength and the negative effect of carbonation in indoor environment using the accelerated carbonation test of 5% CO2 in 50% relative humidity. Three palm oil fuel ash fractions of different fineness, viz., coarse original palm oil fuel ash (CPOA), medium palm oil fuel ash (MPOA) and fine palm oil fuel ash (FPOA) were used for the study. Ordinary Portland cement (OPC) was partially replaced by these palm oil fuel ashes at the dosages of 20% and 40% by weight of binder. The results showed that the incorporation of the ashes affected the strength and the carbonation depths of mortars. The strengths of mortar slightly decreased with the increases in the dosage of the ash. The fineness of ash, on the other hand, improved the strength and the carbonation of the mortars. The mortars containing FPOA exhibited high strength and relatively low carbonation in comparison to those using coarser MPOA and CPOA. The use of FPOA resulted in a strong and dense mortar owing to the increased packing effect and pozzolanic reaction. It was therefore, demonstrated that the FPOA could be used as a pozzolanic material to replace part of Portland cement for use in the indoor environment
Development of Classified Fly Ash as a Pozzolanic Material
This research studies the potential for using classified fly ash from Mae Moh power plant in Thailand as a pozzolanic material.This research studies the potential for using classified fly ash from Mae Moh power plant in Thailand as a pozzolanic material. Three different fly ash finenesses viz., coarse Original Fly Ash (OFA), Medium Fly Ash (MFA) and Fine Fly Ash (FFA) were used for the study. Ordinary Portland Cement (OPC) was partially replaced with fly ash at 20 and 40% by weight of binder. The water to binder ratio was kept constant at 0.5 and the flow of mortar was maintained at 110±5% with the aid of superplasticizer (SP). Compressive strength, carbonation depth and porosity test of mortars were determined. FFA has a high potential to be used as a good pozzolanic material. The use of FFA produces mortars with good strength and low porosity. The resistance to carbonation of mortar improves with partial replacement of FFA in comparison with the normal coarse fly ash. The use of FFA results in a strong and dense mortar which is due to better dispersion and filling effect as well as an increase in the pozzolanic reaction
Pore structure changes of blended cement pastes containing fly ash, rice husk ash, and palm oil fuel ash caused by carbonation
In this paper, the effects of carbonation on pore structure of blended pozzolan cement pastes were investigated. Ordinary Portland cement _OPC_ was partially replaced with ground palm oil fuel ash _POA_, ground rice husk ash _RHA_ and classified fine fly ash _FA_. The strength, total porosity, specific surface area, and pore size distribution were tested.In this paper, the effects of carbonation on pore structure of blended pozzolan cement pastes were investigated. Ordinary Portland cement _OPC_ was partially replaced with ground palm oil fuel ash _POA_, ground rice husk ash _RHA_ and classified fine fly ash _FA_. The strength, total porosity, specific surface area, and pore size distribution were tested. In general, incorporation of pozzolans increased the total porosity of blended cement pastes in comparison to that of OPC paste. Carbonation of pastes under 5% CO2 and 50% relative humidity _RH_ for 28 days resulted in filling of the pore voids and possible attack on calcium silicate hydrate _CSH_ depending on the type of pozzolan used. After carbonation, total porosity decreased and specific surface areas of the blended pozzolan cement pastes reduced indicating the infilling of voids. Pore size distributions of POA and RHA pastes were different to those of FA pastes. Large pores of the POA and RHA pastes were increased indicating coarsening of pores owing to possible attack on CSH. It is possible that POA and RHA were highly reactive and hence their uses resulting in severe carbonation compared to use of FA
Effect of grinding on chemical and physical properties of rice husk ash
The effect of grinding on the chemical and physical properties of rice husk ash was studied. Four rice husk ashes with different finenesses, i.e. coarse original rice husk ash (RHA0), RHA1, RHA2, and RHA3 were used for the study.The effect of grinding on the chemical and physical properties of rice husk ash was studied. Four rice husk ashes with different finenesses, i.e. coarse original rice husk ash (RHA0), RHA1, RHA2, and RHA3 were used for the study. Ordinary Portland cement (OPC) was partially replaced with rice husk ash at 20% by weight of binder. The water to binder ratio (W/B) of the mortar was maintained at 110%±5% with flow table test. Specific gravity, fineness, chemical properties, compressive strength, and porosity test of mortars were determined. The differences in chemical composition of the rice husk ashes with different finenesses from the same batch are small. The use of RHA3 produces the mortars with good strength and low porosity. The strength of the mortar improves with partial replacement of RHA3 in comparison with normal coarse rice husk ash. The use of RHA3 results in a strong and dense mortar, which is due to the better dispersion and filling effect, as well as an increase in the pozzolanic reaction
พัฒนาดินซีเมนต์ลูกรังผสมวัสดุเถ้าทิ้งจากผลผลิตอุตสาหกรรมและเกษตรกรรมเป็นอิฐประสาน
รายงานวิจัย -- มหาวิทยาลัยเทคโนโลยีราชมงคลพระนคร, 2555จากการทดลองวิจัยพบว่าตัวอย่างดินลูกรังผสมเถ้าทิ้งจากอุตสาหกรรมและเกษตรกรรมสามารถเป็นวัสดุก่อสร้างอิฐประสานได้ตามความเหมาะสมตามอัตราส่วนและกาลังที่ต้องการ โดยมีองค์ประกอบทางเคมีของดินลูกรัง, เถ้าแกลบและเถ้าชานอ้อย พบว่าดินลูกรังมีซิลิกอน ออกไซด์ (SiO2), อลูมิน่า ออกไซด์ (Al2O3), ไอรอน ออกไซด์ (Fe2O3) เป็น 58.60 %, 25.50%, 13.00% ตามลาดับและพบสารประกอบ Silicon Oxide (SiO2) : Quartz เถ้าแกลบมีซิลิกอน ออกไซด์ (SiO2), แคลเซียม ออกไซด์ (CaO), โพแทสเซียม ออกไซด์ (K2O) เป็น 94.00%, 2.00%, 2.80% ตามลาดับและพบสารประกอบ Silicon Oxide (SiO2) : Cristobalite เถ้าชานอ้อยมีซิลิกอน ออกไซด์ (SiO2), แคลเซียม ออกไซด์ (CaO), โพแทสเซียม ออกไซด์ (K2O) เป็น 74.7%, 07.8%, 5.4% ตามลาดับและพบสารประกอบ Silicon Oxide (SiO2) : Quartz ผลการทดสอบกาลังอัดพบว่าตัวอย่างทดสอบเถ้าแกลบที่มีกาลังอัดน้อยกว่า 70 ksc. 34 ตัวอย่างระหว่าง 70-100 ksc. 7 ตัวอย่าง และมากกว่า 100 ksc. 24 ตัวอย่าง ตัวอย่างทดสอบเถ้าชานอ้อยที่มีกาลังอัดน้อยกว่า 70 ksc. 25 ตัวอย่างระหว่าง 70-100 ksc. 8 ตัวอย่างและมากกว่า 100 ksc. 32 ตัวอย่าง ซึ้งพบว่าดินลูกรังและเถ้าทิ้งเมื่อเพิ่มปริมาณปูนมากขึ้นกาลังรับแรงเพิ่มตามสาดับผู้ใช้ควรเลือกใช้ตามความเหมาะสมกับงาน ผลการทดสอบการดดูดซึมน้าพบว่าอิฐประสานจากเถ้าแกลบและเถ้าชานอ้อยหลังการแช่น้าไม่สามารคงรูปอยู่ได้ 11 ตัวอย่างซึ่งเห็นว่าไม่มีวัสดุที่ก่อให้เกิดการแข็งตัว อิฐประสานจากเถ้าแกลบและเถ้าชานอ้อยสามารถดูซึมน้าได้น้อยกว่า 30% จานวน 51 ตัวอย่างและ 53 ตัวอย่าง ตามลาดับ ซึ้งสามารถนาไปใช้ในงานก่อสร้างได้ผลการทดสอบการเปลี่ยนแปลงปริมาตรจากความชื้นพบว่าอิฐประสานจากเถ้าแกลบและเถ้าชานอ้อยไม่เกิดการเปลี่ยนแปลงปริมาตรหรือเกิดน้อยมากจานวน 10 และ14 ตัวอย่างตามลาดับซึ้งเป็นคุณสมบัติที่ดีของวัสดุก่อสร้างRajamangala University of Technology Phra Nakho
Use of Rice Husk-Bark Ash in Producing Self-Compacting Concrete
This paper presents the use of blend of Portland cement with rice husk-bark ash in producing self-compacting concrete (SCC). CT was partially replaced with ground rice husk-bark ash (GRHBA) at the dosage levels of 0%–40% by weight of binder. Compressive strength, porosity, chloride penetration, and corrosion of SCC were determined. Test results reveal that the resistance to chloride penetration of concrete improves substantially with partial replacement of CT with a blend of GRHBA and the improvement increases with an increase in the replacement level. The corrosion resistances of SCC were better than the CT concrete. In addition, test results indicated that the reduction in porosity was associated with the increase in compressive strength. The porosity is a significant factor as it affects directly the durability of the SCC. This work is suggested that the GHRBA is effective for producing SCC with 30% of GHRBA replacement level