An assessment method of hydration degree of Rice husk ash blended cement considering temperature effect

2021 ◽  
Vol 304 ◽  
pp. 124534
Author(s):  
Xue Luo ◽  
Xunli Jiang ◽  
Qi Chen ◽  
Zhiyi Huang
Keyword(s):  
Temperature Effect ◽  
Rice Husk ◽  
Rice Husk Ash ◽  
Blended Cement ◽  
Assessment Method ◽  
Hydration Degree

scholarly journals Solidification and Leachability of Cr (VI) in Rice Husk Ash-Blended Cement

2011 ◽  
Vol 2011 ◽  
pp. 1-6 ◽  
Author(s):  
Neeraj Jain
Keyword(s):  
Rice Husk ◽  
Rice Husk Ash ◽  
Setting Time ◽  
Blended Cement ◽  
X Ray Diffraction ◽  
Retention Capacity ◽  
Allowable Limit ◽  
X Ray ◽  
Curing Period ◽  
Leaching Procedure

Investigations carried out to study the effect of Cr (VI) (1000–3000 mg/l) on solidification and hydration behavior of Ordinary Portland cement (OPC) and rice husk ash (RHA) blended (10%, 20%, and 30%) cement show that addition of RHA accelerates final setting as compared to control samples (OPC) and retardation in setting time has been observed on increase in rice husk ash concentration (10%–30%). Solidification studies show that the compressive strength of controls and rice husk ash blended samples increases with increase in the curing period and maximum strength was observed with 20% RHA blended samples. With the increase in Cr (VI) concentrations, the strength of OPC and RHA blended samples decreases as compared to controls (without chromium). The results of Toxicity Characteristics Leaching Procedure (TCLP) test, (pH≅3), show that the retention capacity of OPC and RHA blended samples was in the range of 92% to 99% and the leached Cr (VI) concentration was under the allowable limit (5 mg/l) of U.S. EPA. The chemistry of influence of Cr (VI) on hydration of cement was examined by X-ray diffraction which shows the formation of various crystalline phases during solidification in rice hush ash blended cement.

scholarly journals PHYSICO-CHEMICAL AND MECHANICAL PROPERTIES OF BLENDED CEMENT PASTES CONTAINING RICE HUSK ASH AND METAKAOLIN

2014 ◽  
Vol 25 (1) ◽  
pp. 7-14 ◽  
Author(s):  
S. Abo-El-Enein ◽  
H. Hammad ◽  
T. EL-Sokary ◽  
S. Mekky ◽  
M. Mustafa
Keyword(s):  
Mechanical Properties ◽  
Rice Husk ◽  
Rice Husk Ash ◽  
Blended Cement ◽  
Cement Pastes ◽  
Physico Chemical

scholarly journals Physicochemical Properties of Hydrated Portland Cement Blended with Rice Husk Ash

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Joseph Mwiti Marangu ◽  
Cyprian Muturia M’thiruaine ◽  
Mark Bediako
Keyword(s):  
Compressive Strength ◽  
Portland Cement ◽  
Rice Husk ◽  
Elevated Temperatures ◽  
Rice Husk Ash ◽  
Blended Cement ◽  
Strength Development ◽  
Carbonation Depth ◽  
Blended Cements ◽  
Carbonation Resistance

In the presence of significant quantities of carbon dioxide (CO2) and elevated temperatures in the atmosphere due to climate change, cement-based materials are susceptible to carbonation. Blended cements are more prone to carbonation attack than Portland cement. There is a need to evaluate the carbonation resistance of blended cements in a carbonation-prone environment. This paper presents experimental findings obtained from an evaluation of carbonation resistance tests on Rice Husk Ash- (RHA-) blended cement. The blended cement was made by intergrinding of Portland Cement (PC) and RHA to make the test cement (PC-RHA). The RHA dosage in the PC-RHA was varied from 0 to 30% by mass of PC. Pozzolanicity, standard consistency, and setting time tests were conducted on PC-RHA. Mortar prisms measuring 160 mm × 40 mm x 40 mm were separately cast at a water/cement ratio ( w / c ) of 0.50 and 0.60 and cured in water for 2, 7, 14, 28, and 90 days. Compressive strength tests were conducted on the mortar prisms at each of the testing ages. The prepared mortars were also subjected to accelerated carbonation tests in two Relative Humidity (RH) curing regimes, one maintained at an RH greater than 90% and the other between 50–60%. Carbonation resistance of the mixtures was evaluated in terms of the changes in carbonation depth using a phenolphthalein test at the age of 7, 14, 28, and 56 days of curing in a continuous flow of CO2. Compressive strength measurements were also taken during each of the carbonation testing ages. For comparison, similar tests were conducted using commercial PC. The results showed that PC-RHA was pozzolanic while PC was nonpozzolanic. Higher water demand and longer setting times were observed in PC-RHA than in PC. Moreover, there was increased strength development in water-cured samples with increased curing duration. Carbonation results indicated that there was a marked increase in carbonation depth with increased dosage of RHA in PC-RHA binders, increased duration of exposure to CO2, and decreased RH (RH between 50–60%). PC-RHA binders exhibited lower carbonation resistance than PC. In conclusion, for mortars at any w / c ratio, carbonation resistance decreased with increase in RHA dosage and increased w / c ratio.

Effect of Rice Husk Ash Fineness on the Properties of Concrete

2014 ◽  
Vol 554 ◽  
pp. 203-207 ◽  
Author(s):  
Sri Jayanti Dewi ◽  
Putra Jaya Ramadhansyah ◽  
Abdul Hassan Norhidayah ◽  
A. Aziz Md. Maniruzzaman ◽  
Mohd Rosli Hainin ◽  
...  
Keyword(s):  
Rice Husk ◽  
Permeability Coefficient ◽  
Rice Husk Ash ◽  
Gas Permeability ◽  
Blended Cement ◽  
Target Strength ◽  
Cement Concrete ◽  
Mechanical Grinding ◽  
Binder Ratio ◽  
Water To Binder Ratio

In the present research, the effect of rice husk ash fineness on the properties of concrete was studied. Eight different fineness grades of rice husk ash were examined. A rice husk ash dosage of 15% by weight of binder was used throughout the experiments. The water-to-binder ratio was 0.49 to produce concrete having target strength of 40MPa at 28 d. Workability, compressive strength and gas permeability tests were carried out to identify the properties of concrete. The results revealed that increasing the fineness of RHA by mechanical grinding was found to improve the workability of RHA blended cement concrete. In addition, the use of RHA3 with mean particle size of 9.52μm produces the concrete with good strength. Finally, significant improvement was observed in mixtures incorporating RHA in terms of permeability coefficient.

Strength of Concrete Containing Rice Husk Ash Subjected to Sodium Sulfate Solution via Wetting and Drying Cyclic

2014 ◽  
Vol 534 ◽  
pp. 3-8 ◽  
Author(s):  
Che Wan Che Norazman ◽  
Ramadhansyah Putra Jaya ◽  
Sri Jayanti Dewi ◽  
Badorul Hisham Abu Bakar ◽  
M.A. Fadzil
Keyword(s):  
Compressive Strength ◽  
Rice Husk ◽  
Sodium Sulfate ◽  
Rice Husk Ash ◽  
Blended Cement ◽  
Sulfate Solution ◽  
Target Strength ◽  
Type I ◽  
Cement Concrete ◽  
Cement Replacement

The influences of different replacement levels of rice husk ash (RHA) blended cement concrete subjected to 5% Na2SO4 solution via wetting-drying cycles was evaluated in this study. RHA was used as a Portland cement Type I replacement at the levels of 0%, 10%, 20, 30%, and 40% by weight of binder. The water-to-binder ratio was 0.49 to produce concrete having target strength of 40 MPa at 28 days. The performance of RHA blended cement concrete on compressive strength, reduction in strength and loss of weight was monitored for up to 6 months. The results of the compressive strength test have been shown that use of RHA in blended cement has a significant influence on sulfate concentration. When increasing the replacement level of RHA, the strength of concrete also increases in comparison to OPC concrete (except RHA40) even exposed to 5% Na2SO4 solution. On the other hand, the reduction in strength and weight loss of specimens increased with increase in the exposure time. Generally, it can be said that the incorporation of rice husk ash as cement replacement significantly improved the resistance to sulfate penetration of concrete. Finally, RHA cement replacement in concrete mixed provided better resistance to sodium sulfate attack up to 6-month exposure.

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