scholarly journals Use of Rice Husk Ash Blended Cement to Produce Cement Sand Blocks: Optimal Level of Cement Replacement for Compressive Strength

Author(s):  
D. A. R. DoIage ◽  
K. Mylvaganam ◽  
P. Mayoorathan ◽  
S. Inparatnam
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

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.


2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Joseph Mwiti Marangu ◽  
Cyprian Muturia M’thiruaine ◽  
Mark Bediako

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.


2018 ◽  
Vol 775 ◽  
pp. 624-629
Author(s):  
Kantapong Boontawee ◽  
Withit Pansuk ◽  
Luangvaranunt Tachai ◽  
Katsuyoshi Kondoh

Rice husk ash (RHA) is used as a replacement to cement to produce mortar. The effect of 5, 10, and 15wt% addition to the density and compressive strength of mortar is investigated. It was found that with the increasing addition of RHA causes the decrease of compressive strength and density of mortars. Compressive strength of mortar drops with addition of RHA, from a value of 42 MPa of no RHA addition, to 24 MPa of 15wt% RHA addition. Reduction in compression strength may be due to the decrease in density, which arises from porous RHA. This is more dominant in mortar made from addition of RHA without prior acid treated. Carbon residue and impurity in RHA further reduce the compressive strength of mortar. In addition, this research validate the use of a more environmentally friendly citric acid for partially removal of oxide impurities prior to burning the rice husk.


2014 ◽  
Vol 803 ◽  
pp. 288-293 ◽  
Author(s):  
Mustaqqim Abdul Rahim ◽  
Norlia Mohamad Ibrahim ◽  
Zulliza Idris ◽  
Zuhayr Md Ghazaly ◽  
Shahiron Shahidan ◽  
...  

The use of pozzolanic material from waste product as partial cement replacement in concrete contribute to reduce the environmental, economic problem through their waste and as well enhance the strength and properties of concrete. Rice husk ash (RHA) is one of the industrial waste that suitably used as a cement replacement due to its pozzolanic properties which can enhance the properties of concrete. In this study, the workability, compressive strength and water absorption of the concrete containg RHA is investigating. The chemical content of RHA also investigated by using X-ray Fluorescence Test (XRF). The different RHA percentage of 5%, 15% and 25% were used in this study with burning temperature 650°C. The concrete cube of size 100 mm x 100 mm x 100 mm were prepared and cured for 7, 14 and 28 days. Based on result, it was concluded that the optimum RHA replacement for cement in this report was 5 %, which provided the highest compressive strength at 28 days.


Author(s):  
Akeem Ayinde Raheem ◽  
Mutiu A. Kareem

Applications of agricultural by-product as substitute for non-renewable material in cement production are desirable in stimulating socio-economic development. In this study, Rice Husk Ash (RHA) blended cement was produced by replacing 5%, 7%, 11.25%, 15%, 20.25% and 25% by weight of Ordinary Portland Cement (OPC) clinker with RHA. The cement without RHA serves as the control. The chemical compositions of RHA, OPC-clinker and the blended cements were determined using X-ray fluorescence analyzer. The physical characteristics of RHA blended cements that were considered are fineness, soundness, consistency, initial and final setting times and compressive strength at 2, 7, 28, 56 and 90 curing ages. The results showed that RHA is a suitable material for use as a pozzolan as it satisfied the minimum requirement by having the sum of SiO2, Al2O3 and Fe2O3 of more than 70%. Incorporation of RHA led to an increase in the composition of SiO2 and reduction in that of CaO. An increase in RHA content showed a decrease in compressive strength at early ages and slightly increase at a later age (90 days). The blended cement produced with lower levels of RHA replacement conforms to standard specifications specified in BS EN 197-1:2000, NIS 439:2000 and ASTM C 150-02. The minimum Strength Activated Index (SAI) of 75% at the age of 28 days of curing as specified by ASTM C 618 was satisfied by RHA replacement of up to 15%. It was concluded that blended cement with the maximum of 15% RHA content is suitable for use for structural purposes.


Author(s):  
Zaidatul Syahida Adnan ◽  
Nur Farhayu Ariffin ◽  
Sharifah Maszura Syed Mohsin ◽  
Nor Hasanah Abdul Shukor Lim

Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3216
Author(s):  
Jin Li ◽  
Peiyuan Chen ◽  
Haibing Cai ◽  
Ying Xu ◽  
Chunchao Li

In this study, rice husk ash (RHA) was explored as a strength enhancer for mortars containing waste rubber. The effects of RHA on the flow, mechanical strength, chloride resistance, and capillary absorption of rubber mortar were investigated by substituting up to 20% cement with RHA. The experimental results showed that the incorporation of rubber into mortar could be safely achieved by adding RHA as a cement substitute by up to 20% without compromising the compressive strength of mortar. Moreover, the RHA also exerted positive effects on the enhancement of the chloride resistance as well as the capillary absorption of rubber mortars, for which 15% RHA was found to be the optimal dosage.


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