จำนวน Repository ( 12 )
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.
การพัฒนาปูนดิบจากเปลือกหอยครางเพื่อส่งเสริมวิสาหกิจชุมชน
This research aimed to study the optimum conditions for making raw lime from shells which consisted of 9 conditions: calcined at three levels of 700 800 and 900 degrees Celsius for 1 2 and 3 hours. Calcium element content in raw lime using X-ray fluorescence (XRF) measurement and structural analysis of calcium compounds by X-Ray Diffraction (XRD). The research results were found. 1. Optimal conditions for making lime mortar are temperature 800 degrees Celsius duration 2 hours. The physical characteristics of raw lime are white and porous. 2. The calcium content from the shells calcination at 800 degrees Celsius for 1 2 and 3 hours was 98.22% 96.70% 97.89%. 3. Changes in the calcium compounds of raw lime obtained by calcining the shell at 800 degrees Celsius for 1 hour were mainly found in the form of calcium carbonate (CaCO3). At 2 3 hours calcium carbonate (CaCO3) is mostly converted to form calcium hydroxide (Ca(OH)2)compound calcium oxide (CaO) compound is formed.
ผลของน้ำมันเครื่องใช้แล้วต่อสมบัติของมอร์ต้าร์หินพัมมิซผสมเถ้าไม้ยางพารา
Properties of pumice aggregate mortar blended with para rubber wood fly ash (PRWFA) replaced type 1 ordinary Portland cement (OPC) in different proportions of 020 and 40 wt.% OPC and dosed with used engine oil (UEO) in proportions of 00.2 and 0.3 wt% water were investigated. Whole mix type specimens size was cast in 555 cm and curing in ambient temperature for 7 and 28 days. Testing series of physico-mechanical properties performed on bulk density water absorption electrical resistivity Shore hardness and compressive strength were determined. Moreover microstructure via scanning electron microscope was analyzed. Effect of curing ages enhanced properties of samples such as electrical resistivity Shore hardness and compressive strength. Particularly the 28-day specimen that contained 20wt.% PRWFA and 0.2wt.% UEO provided bulk density of 1.61 g/cm3 and highest compressive strength of 22.09 MPa.
An Experimental investigation of the carbonation of blended portland cement palm oil fuel ash mortar in an indoor environment
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.
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). 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.