scholarly journals Effect of Rice Husk Ash (RHA) and Slag as Partial Replacement of Cement on Reinforced Concrete Slabs

Author(s):  
Mohamed Nabil ◽  
Ashraf Essa ◽  
Magdy Mahmoud ◽  
Mohamed Rabah

The increasing demand and consumption of cement have necessitated the use of slag, fly ash, rice husk ash (RHA), and so forth as a supplement of cement in concrete construction. The aim of the study is to develop a replacement of the cement with rice husk ash and slag combined with chemical activator. NaOH, Ca(OH)2, and KOH were used in varying weights and molar concentrations. Partial replacement of cement was tested for its consistency, setting time, flow, compressive strength, and fire. The consistency and setting time of the Partial Z-Cement (Zero cement) paste increase with increasing RHA content. The replacement of cement mortar achieves a compressive strength of 22–25MPa at  28 days with 5% NaOH or at 2.5or non used activator molar concentrations. The tested slabs were made of concrete and reinforced with bars with 10 mm diameter having and compressive strength evaluated from the compressive tests. The analysis of the slab deflection behavior has been presented after fire of samples. The results show the different character of the load-deflection relationship of a replacement of the cement with rice husk ash and slag reinforced slabs compared to traditionally reinforced slabs.  

2015 ◽  
Vol 2015 ◽  
pp. 1-14 ◽  
Author(s):  
M. R. Karim ◽  
M. F. M. Zain ◽  
M. Jamil ◽  
F. C. Lai

The increasing demand and consumption of cement have necessitated the use of slag, fly ash, rice husk ash (RHA), and so forth as a supplement of cement in concrete construction. The aim of the study is to develop a zero-cement binder (Z-Cem) using slag, fly ash, and RHA combined with chemical activator. NaOH, Ca(OH)2, and KOH were used in varying weights and molar concentrations. Z-Cem was tested for its consistency, setting time, flow, compressive strength, XRD, SEM, and FTIR. The consistency and setting time of the Z-Cem paste increase with increasing RHA content. The Z-Cem mortar requires more superplasticizer to maintain a constant flow of110±5% compared with OPC. The compressive strength of the Z-Cem mortar is significantly influenced by the amounts, types, and molar concentration of the activators. The Z-Cem mortar achieves a compressive strength of 42–44 MPa at 28 days with 5% NaOH or at 2.5 molar concentrations. The FTIR results reveal that molecules in the Z-Cem mortar have a silica-hydrate (Si-H) bond with sodium or other inorganic metals (i.e., sodium/calcium-silica-hydrate-alumina gel). Therefore, Z-Cem could be developed using the aforementioned materials with the chemical activator.


In this research work, the effect of rice husk ash on concrete produced with cellulose industrial residue was studied. A mix proportion of 1:1.8:3.7 with water cement ratio of 0.47 were used. The percentage replacement of Ordinary Portland Cement (OPC) with cellulose industrial residue and rice husk ash used were 0%, 5%, 10%, 20% 30% and 40%. Concrete cubes of 150mm x 150mm x 150mm of Ordinary Portland Cement/Cellulose Industrial Residue and Ordinary Portland Cement/Cellulose Industrial Residue/Rice Ash were cast and cured at 3,7,28,60 and 90 days respectively. At the end of each hydration period, the concrete cubes were crushed and their compressive strength were determined. The result of compressive strength of 5-40% replacement of cement with cellulose industrial residue ranges from 13.02-32.81 N/mm2 as against 25.60-42.08N/mm2 for the control test. The result of the compressive strength of 5-40% replacement of cement with Cellulose Industrial Residue and Rice Husk Ash ranges from 13.17-36.30N/mm2 as against 25.60-42.08N/mm2 for the control test. The result of the initial and final setting time of Ordinary Portland Cement/Cellulose Industrial Residue and Cement/Cellulose Industrial Residue/Rice Husk Ash for 5-40% replacement of cement ranges from 61-118mins, 58-110mins and 620 – 836mins, 598 – 799mins respectively as against 52mins and 590mins for the control test. The main conclusion of this study is that the incorporation rice husk ash into cellulose industrial residue increase the strength of concrete produced. The objective of this study is to assess the strength of concrete produced when two pozzolanic materials were used to replace cement in producing concrete.


Author(s):  
Musaib Bashir Dar

Abstract: In this developing era concrete and cement mortar are widely used by the construction industry, with this development. Large number of industrial wastes are generated and if these wastes are not properly used it will create severe problems, keeping the environment in mind, concrete engineers are trying to find some alternative materials which will not only replaces the cement content but also improves strength of concrete. As we also know that during the manufacturing of cement large amount of Co2 is released into the environment, but if we use such material that will replace the quantity of cement content therefore indirectly, we are contributing towards the prevention of our planet from global warming and other pollutions. Also, in this research work the Rice Husk Ash is used. the rice husk ash obtained from the rice processing units, by adding this product with concrete, not only replaces the cement content but also increases the strength of concrete like compressive strength etc. The Rice husk ash was incorporated with concrete with varying percentages of 2.5% ,5% ,7.5%, & 10%. the proper codal precautions were followed during the manufacture of concrete cubes of 150x150x150mm. it was concluded that the strength of concrete increased by incorporated the rice husk ash. Keywords: Concrete, RHA, Compressive strength, Industrial wastes, Cement etc


2020 ◽  
Vol 13 (3) ◽  
pp. 315-321
Author(s):  
Dhiraj Ahiwale ◽  
Rushikesh Khartode

Now days, the waste rice husk from rice mill, marble powder from tile industry and fly ash from steam power plant are necessary to utilize as partial replacement of cement for concrete production. Large scale production of cement required consumption of raw materials and energy as well as emissions to air which posse’s environmental threat in various areas of country. Apart from the environmental threat, there still exists the problem of shortage in many areas. Therefore, substitute material for concrete needs to be considered. The paper aims to analyze the compressive strength of concrete cubes and flexural strength of concrete beams made from partially replaced cement, sand, and coarse aggregate. This research study adopted in laboratory on 48 total specimens of grade M25 concrete cubes of size 150x150x150mm and concrte beams of size 100x100x500mm were casted. Out of the 48 concrete specimens cast, 6 each were made out 10%, 20%, and 30 % replacement of fly ash, rice husk ash and marble powder to cement in concrete. It was found that the compressive strength and flexural strength of concrete made from the mixture of 20 % partially replaced cement, sand and coarse aggregate was similar than the concrete made from without replaced cement , sand and coarse aggregate.


Author(s):  
Joseph A. Ige ◽  
Mukaila A. Anifowose ◽  
Samson O. Odeyemi ◽  
Suleiman A. Adebara ◽  
Mufutau O. Oyeleke

This research assessed the effect of Nigerian rice husk ash (RHA) and calcium chloride (CaCl2) as partial replacement of cement in concrete grade 20. Rice husk ash (RHA) is obtained by combustion of rice husk in a controlled temperature. The replacement of OPC with rice husk ash (RHA) were 0%, 5%, 10%, 15% and 20%. 1% of Calcium Chloride was blended with OPC/RHA in all the test specimens except from control mix. Concrete cubes of sizes 150mm x 150mm x 150mm were cast and cured in water for 7, 14 and 28 days respectively. Slump test was conducted on fresh concrete while density test and compressive strength test were conducted on hardened concrete. The slump results revealed that the concrete becomes less workable (stiff) as percentage increases. The compressive strength result at 28 days revealed that 5%RHA/1%CaCl2 have the highest strength of 26.82N/mm2 while 20%RHA/1%CaCl2 have the lowest strength (21.48N/mm2). Integration of 5%RHA/1%CaCl2 and 10%RHA/1%CaCl2 as cement replacement will produce a concrete of higher compressive strength compared to conventional concrete in grade 20 concrete.


Reactive Powder Concrete (RPC) is a special concrete with excellent mechanical and durability properties and it is differentiated with other forms of concrete in terms of production, mix proportion etc. Depending upon various parameters like composition and the curing temperature, its compressive strength ranges from 130 MPa to 750 MPa, bending strength varies as 29 to 51 MPa and Young's modulus results upto 50GPa to 75GPa.Though RPC possesses many outstanding properties, it has limited applications in the construction field. The usage of higher quantity of cement and Silica Fume causes the rise of production of RPC. In addition to that, the silica fume availability is also restricted. For a country like India, usage of SF is limited due to its high price. Also, mineral admixtures can be used as a suitable alternative. Hence in this research work, Rice Husk Ash (RHA) is used as a possible alternatives for replacing silica fume in RPC. RHA holds maximum amount of silica (approx. 96%) in amorphous form. In this research, an experimental research on mechanical and durability properties of RPC by partially replacing SF with RHA. The detailed literature survey on constituent materials, mix proportions and curing conditions of RPC were done. Also, the optimum temperature and duration for the thermal treatment of RHA were identified. The compressive strength of the specimens of partial replacement of Silica Fume using RHA were tested and the results were compared with control specimens compressive strength.


Crystals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 779
Author(s):  
Muhammad Nasir Amin ◽  
Ammar Iqtidar ◽  
Kaffayatullah Khan ◽  
Muhammad Faisal Javed ◽  
Faisal I. Shalabi ◽  
...  

Efforts are being devoted to reducing the harmful effect of the construction industry around the globe, including the use of rice husk ash as a partial replacement of cement. However, no method is available to date to predict the compressive strength (CS) of rice husk ash blended concrete (RHAC). In this study, advanced machine learning techniques (artificial neural network, artificial neuro-fuzzy inference system) were used to predict the CS of RHAC. Based on the published literature, six inputs, i.e., age of specimen, percentage of rice husk ash, percentage of superplasticizer, aggregates, water, and amount of cement, were selected. Results obtained from machine learning methods were compared with traditional methods such as linear and non-linear regressions. It was observed that the performance of machine learning methods was superior to traditional methods for determining the CS of RHAC. This study will prove beneficial in minimizing the cost and time of executing laboratory experiments for designing the optimum content portions of RHAC.


Sign in / Sign up

Export Citation Format

Share Document