scholarly journals The Influence of Finely Ground Mineral Admixture (FGMA) on Efflorescence

2013 ◽  
Vol 4 (1) ◽  
pp. 50-55 ◽  
Author(s):  
Ong Ming Wei ◽  
Norsuzailina Mohamed Sutan
Keyword(s):  
Calcium Carbonate ◽  
Chemical Analysis ◽  
Mineral Admixture ◽  
Partial Replacement ◽  
Cement Ratio ◽  
Water Cement Ratio ◽  
Cement Replacement ◽  
Carbonate Formation

Efflorescence phenomenon on concrete is not new and found in the form of white deposits on surfaces of concrete. Incorporation of Finely Ground Mineral Admixture (FGMA) in concrete to prevent occurrence of efflorescence is based on reduction of portlandite, densified microstructure and thus enhanced watertightness. The magnitude of efflorescence in term of percentage of calcium carbonate formation of FGMA modified mortar were evaluated at water-cement ratio of 0.3, 0.4 and 0.5 with 10%, 20%, and 30% of cement replacement by weight. The samples were tested with chemical analysis at 7, 14, 21, 28, 60 and 90 days. The FGMA additions into mortar were comparing with ordinary mortar to evaluate enhanced performance of FGMA modified mortar toward efflorescence. The results of this experiment showed that addition of FGMA into mortar caused less formation of calcium carbonate as partial replacement of cement with certain w/c ratio and percentage of cement replacement.

scholarly journals Water Requirement of Concrete with Mineral Admixtures

2021 ◽  
Vol 9 (VI) ◽  
pp. 4573-4577
Author(s):  
Alka A. Avasthi
Keyword(s):  
Particle Size ◽  
Water Content ◽  
Surface Area ◽  
Agricultural Waste ◽  
Water Requirement ◽  
Mineral Admixtures ◽  
Partial Replacement ◽  
Cement Ratio ◽  
Water Cement Ratio ◽  
Cement Replacement

India is one of the leading producers of sugar and rice, hence agricultural waste is generated in huge quantities in India leading to potential disposal problems without effective management techniques. However, the economic importance of this solid waste has been realised with several applications like adsorbents, filters, ceramics, briquettes, bricks, and blocks and soil amendment activities. Cement is one of the most universally used material. Cement production is an environmental threat as well as the production cost is also very high. Manufacturing of cement and its use is also one of the causes of global warming Environmentalists and Researchers around the world are searching for better options to replace cement As cement replacement materials mineral admixtures are nowadays gaining mileage as they address two problems. First is the waste management of agricultural wastes, which causes air pollution due to open air burning and the second is reducing the demand for cement. Hence in addition to reducing the cost it also reduces the hazardous effect that it has on the environment. In general, the particle size of these admixtures play an important role in making the concrete dense, but low particle size leads to increased surface area and more requirement their surface area increases and workability reduces. Hence to make the concrete workable the water requirement also increase [1].Generally the water requirement or the water cement ratio for normal concrete is between 0.35 to 0.5 , depending on the cement content and the mix design . For high strength concrete where the quantity of cement increases the water cement ratio also increases. But in concrete with mineral admixtures the water cement ratio is more than 0.6. The present paper deals with the water requirement for the concrete with cement replacement with mineral admixtures , The two types of admixtures water requirement of concrete with partial replacement of cement with sugarcane bagasse ash and rice husk ash in different proportions of 5 % , 10%, 15% , 20%, 25% and 30 % , earlier as a binary mix replacing the mineral admixtures individually and later together as a ternary mix using both the mineral admixtures together. The results indicate increase in water content with the increase in cement replacement proportions in both the binary and ternary mix . The increase in water content does not hamper the compressive strength of the binary and ternary mix , but in some cases increases it.

scholarly journals Effect of Rice Husk Ash and Water-Cement Ratio on Strength of Concrete

2018 ◽  
Vol 4 (10) ◽  
pp. 2373 ◽  
Author(s):  
Naraindas Bheel ◽  
Shanker Lal Meghwar ◽  
Suhail Ahmed Abbasi ◽  
Lal Chand Marwari ◽  
Jabbar Ahmed Mugeri ◽  
...  
Keyword(s):  
Rice Husk ◽  
Rice Husk Ash ◽  
Research Work ◽  
Testing Machine ◽  
The Body ◽  
Mineral Admixture ◽  
Partial Replacement ◽  
Cement Ratio ◽  
Water Cement Ratio ◽  
Splitting Test

In present status quo, number of researcher are working on waste materials as potential supplement for any of the constituent of concrete to cope with sustainable development. As, the ingredients which constitute the body and give strength to concrete are natural available limited material and has to deplete one day. Thus, there is desperately need of alternate that may replace the limited natural resources. In this regard, this study focuses the rice husk ash (waste stuff) as partial replacement of cement and its possible impact on strength of concrete. In addition, this research work also this research work is conducted to investigate the effect of water-cement ratio on the strength of concrete at 10% partially replacement of Rice husk ash (RHA) by the weight of cement. RHA is a mineral admixture obtained by burning husk at certain temperature. Since as per pervious researches, the physical and chemical properties of RHA are very reactive Pozzolans and possess binding properties so can be used as cement supplement. Therefore, for laboratory experimental work, total 144 cubical and 72 cylindrical. In this research, number of concrete specimens were cast and tested at 1:2:4 mix ratio with various w/c ratios i.e. 0.45, 0.50 and 0.60. Further, at each specified water-cement ratio, two mechanical properties (compressive and splitting tensile strength) were determined in Universal Testing Machine (UTM). These physical properties of concrete were investigated at 7, 14, 28 and 56 days curing period. The experimental results show that the compressive strength gets increased up to 14.51% and tensile splitting test strength increased up to 10.71% at the w/c ratio of 0.45. The workability of plain fresh concrete at all w/c ratios is slightly greater than the workability of concrete blended with 10% RHA. Thus, RHA improves the properties of concrete when used in specific amount. As a result, it can reduce the overall cost of construction and it will reduce the adverse environmental effect. 

Research on Fresh Concrete Water-Cement Ratio Based on Resistivity Method

2016 ◽  
Vol 847 ◽  
pp. 469-475 ◽  
Author(s):  
Hai Bo Ren ◽  
Jian Yin ◽  
Zheng Hui Sang ◽  
Ting Gao
Keyword(s):  
Fresh Concrete ◽  
Mineral Admixture ◽  
Cement Ratio ◽  
Water Cement Ratio ◽  
Resistivity Method ◽  
Concrete Quality ◽  
Resistivity Variation ◽  
The Law ◽  
Concrete Resistivity ◽  
The Impact

Water-cement ratio is an important parameter of concrete quality. Rapid measurement of fresh concrete water-cement ratio can effectively monitor the on-site concrete quality management and play a great role in quality control. We study the variation of fresh concrete resistivity with the aid of electrodeless cement concrete resistivity meter, and discuss the impact of water-cement ratio under different varieties of cement, mineral admixture, chemical admixtures conditions on fresh concrete resistivity. We establish the relationships between fresh concrete resistivity and water-cement ratio based on the law of Portland cement initial hydration resistivity. The studies show that: fresh concrete resistivity is most vulnerable to the changes of water-cement ratio; there is a correlation between the law of fresh concrete resistivity and water-cement ratio; according to the fresh concrete resistivity variation, we can quickly identify water-cement ratio, cement and other parameters.

scholarly journals SUITABILITY OF BURNT AND CRUSHED COW BONES AS PARTIAL REPLACEMENT FOR FINE AGGREGATE IN CONCRETE

2017 ◽  
Vol 36 (3) ◽  
pp. 686-690
Author(s):  
NM Ogarekpe ◽  
JC Agunwamba ◽  
FO Idagu ◽  
ES Bejor ◽  
OE Eteng ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Partial Replacement ◽  
Fine Aggregate ◽  
Cement Ratio ◽  
Water Cement Ratio ◽  
Fine Aggregates ◽  
Concrete Mix ◽  
Average Compressive Strength ◽  
Curing Age

The suitability of burnt and crushed cow bones (BCCB) as partial replacement for fine aggregate in concrete was studied. The percentages of replacements of fine aggregates of 0, 10, 20, 30, 40 and 50%, respectively of BCCB were tested considering 1: 2: 4 and 1: 11/2 :3 concrete mix ratios. The cow bones were burnt for 50 minutes up to 92oC before being crushed. Ninety-six (96) concrete cubes of 1: 2: 4 mix ratio and ninety-six (96) concrete cubes of 1 : : 3 mix ratio measuring 150x150x150mm were tested for the compressive strength at 7, 14, 21 and 28 days respectively. The research revealed that the BCCB acted as a retarder in the concrete. Water-cement ratio increased with the increase in the percentage of the BCCB. The mixes of 1:2:4 and 1::3 at 28 days curing yielded average compressive strengths in N/mm2 ranging from 16.49 - 24.29 and 18.71 - 29.73, respectively. For the mix ratios of 1:2:4 and 1:: 3 at 28 days curing age,  it was observed that increase in the BCCB content beyond 40 and 50%, respectively resulted to the reduction of the average compressive strength below recommended minimum strength for use of concrete in structural works.http://dx.doi.org/10.4314/njt.v36i3.4

Microscopic Mechanism of the Diffusivity of Concrete Chloride Ion

2013 ◽  
Vol 773 ◽  
pp. 687-692 ◽  
Author(s):  
Jun Liu ◽  
Feng Xing ◽  
Bi Qing Dong
Keyword(s):  
Fly Ash ◽  
Early Stage ◽  
Great Influence ◽  
Chloride Ion ◽  
Test Method ◽  
Mineral Admixture ◽  
Microscopic Mechanism ◽  
Cement Ratio ◽  
Water Cement Ratio ◽  
The Impact

Use concrete specimens with different mix proportions to conserve them for 90d taking into account the influence of mineral admixture material---fly ash. Then adopts the RCM test method to measure the rapid diffusivity of chloride ion of concrete and observes the microstructure of the cement paste using the SEM (scanning electron microscopy), aiming to study the impact of fly ash on its hydration process. The results show that the micro-pore structure of the concrete has a great influence on the rapid diffusivity of chloride ion, while its diffusivity is closely related with the water-cement ratio of concrete; after the fly ash is added, the ettringite generation of the concrete in the early stage decreases, and the interspace of the transition zone between the hydrated particles and hydration slurry is enlarged, coupled with the increase in the intercommunicating pore; after curing for 90d, the chloride ion diffusivity decreases significantly with the increase in the dosage of fly ash. For the concrete with the fly ash dosage of 15%, its chloride ion diffusivity is only 75.4% of that with the same water-cement ratio; when its fly ash content is 30%, its chloride ion diffusivity is only 32.3% of the ordinary concrete.

scholarly journals Pore Filling Effect of Forced Carbonation Reactions Using Carbon Dioxide Nanobubbles

Materials ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 4343
Author(s):  
Jihoon Kim ◽  
Ryoma Kitagaki ◽  
Heesup Choi
Keyword(s):  
Carbon Dioxide ◽  
Aqueous Solution ◽  
Surface Modification ◽  
Calcium Carbonate ◽  
Pore Filling ◽  
Concrete Repair ◽  
Mortar Specimen ◽  
Cement Ratio ◽  
Water Cement Ratio ◽  
Series Of Experiments

Various methods for repairing and modifying concrete surfaces have been proposed and applied to improve the durability of existing concrete structures. Surface modification through forced carbonation is a method of densification that forms calcium carbonate in the pores on the surface of concrete to improve its durability. In this study, to evaluate the applicability of this surface modification method to existing buildings, a series of experiments was conducted in which mortar specimens were repeatedly immersed in a carbon dioxide nanobubble aqueous solution. By evaluating the weight change and absorption rate, it was determined that the higher the water/cement ratio of the mortar specimen, the higher the pore filling effect owing to immersion in the carbon dioxide nanobubble aqueous solution. In addition, the effect of clogged pores generated by the precipitation of calcium carbonate was confirmed, and it was found that the higher the water/cement ratio of the mortar specimen, the higher the pore filling effect due to clogging. We believe that our findings contribute to the development of research and construction practices associated with concrete repair and restoration.

Effect of Substitution of Crushed Waste Glass as Partial Replacement for Natural Fine and Coarse Aggregate in Concrete

2016 ◽  
Vol 866 ◽  
pp. 58-62 ◽  
Author(s):  
Oluwarotimi M. Olofinnade ◽  
Julius M. Ndambuki ◽  
Anthony N. Ede ◽  
David O. Olukanni
Keyword(s):  
Coarse Aggregate ◽  
Waste Glass ◽  
Glass Content ◽  
Partial Replacement ◽  
Hardened Concrete ◽  
Fine Aggregate ◽  
Cement Ratio ◽  
Water Cement Ratio ◽  
Concrete Production ◽  
Concrete Mix

Reusing of waste glass in concrete production is among the attractive option of achieving waste reduction and preserving the natural resources from further depletion thereby protecting the environment and achieving sustainability. This present study examines the possible reuse of waste glass crushed into fine and coarse aggregate sizes as partial substitute for natural fine and coarse aggregate in concrete. The variables in this study is both the fine and coarse aggregate while the cement and water-cement ratio were held constant. The crushed glass was varied from 0 – 100% in steps of 25% by weight to replace the both the natural fine and coarse aggregate in the same concrete mix. Concrete mixes were prepared using a mix proportion of 1:2:4 (cement: fine aggregate: coarse aggregate) at water-cement ratio of 0.5 targeting a design strength of 20 MPa. Tests were carried out on total number of 90 concrete cube specimens of size 150 x 150 x150 mm and 90concrete cylinder specimens of dimension 100 mm diameter by 200 mm height after 3, 7, 14, 28, 42 and 90 days of curing. Test results indicated that the compressive and split tensile strength of the hardened concrete decreases with increasing waste glass content compared with the control. However, concrete mix made with 25% waste glass content compared significantly well with the control and can be suitably adopted for production of light weight concrete.

Effects of Temperature on Drying Shrinkage of Concrete

2014 ◽  
Vol 584-586 ◽  
pp. 1176-1181 ◽  
Author(s):  
Ying Zi Yang ◽  
Mao Guang Li ◽  
Hong Wei Deng ◽  
Qi Liu
Keyword(s):  
Fly Ash ◽  
Silica Fume ◽  
Drying Shrinkage ◽  
Shrinkage Strain ◽  
Mineral Admixture ◽  
Cement Ratio ◽  
Water Cement Ratio ◽  
Granulated Blast Furnace Slag ◽  
Influence Of Water ◽  
Effects Of Temperature

The present study investigated experimentally effects of temperature on drying shrinkage of concrete in different water cement ratio and containing mineral admixture. Concrete was exposed to a controlled environment of 20±1oC, 35±1oC, 50±1oC, and 60% ± 5 RH, respectively. The drying shrinkage of concretes with water cement ratio of 0.3, 0.4 and 0.5 were evaluated. The resuluts showed that with the increase of temperature from 20 oC to 50 oC, the influence of water cement ratio on drying shrinkage of concrete was gradually weakened. The shrinkage strain of concretes with replacement of cement by 20% of ground granulated blast-furnace slag (GGBS), 10% of silica fume (SF), and 20% of fly ash (FA) were measured, respectively. Test results showed that GGBS had a little impact on drying shrinkage of concrete; Silica fume could increase the drying shrinkage of concrete significantly in the early and later ages, especially when concrete was subjected to high temperature; Fly ash reduced drying shrinkage in early ages and increased drying shrinkage of concrete in the later ages.

scholarly journals Chicken Feather Ash (CFA) as a Partial Replacement of Cement in Concrete

2021 ◽  
pp. 130-140
Author(s):  
Victor Emeka Amah ◽  
Ejikeme Ugwoha ◽  
Jahswill Macaulay
Keyword(s):  
Compressive Strength ◽  
Partial Replacement ◽  
Chicken Feather ◽  
Cement Ratio ◽  
Water Cement Ratio ◽  
Chicken Feathers ◽  
Allowable Range ◽  
Full Factorial ◽  
Optimum Water ◽  
Curing Age

Every day, large quantities of chicken feathers are disposed of as waste at markets where birds are slaughtered and sold for meat. The possibility of using Chicken feather ash (CFA) as a partial replacement of cement in the concrete making was investigated. Water-cement ratio and percentage CFA used for replacement were chosen as variables in the design of the experiment. Compressive strength and workability were chosen as the required responses to observe and analyzed using response surface methodology. Full factorial design was used for the design of experiment, with CFA replacement and water-cement ratio ranging from 2 – 11% and 0.3 – 0.7 % by mass respectively. There were 27 trial mixes and the freshly made concrete mix was tested for workability. Concrete cubes were molded and cured for 7 and 14 days and were crushed to determine the compressive strength. It was found that as the CFA percentage increases, the workability of the concrete increases making it more fluid. The optimum water-cement ratio was observed to range from 0.49 to 0.51 % as the curing age increases. The optimum compressive strength was observed to range from 15.6 to 18.6 N/mm2 as the curing age increased. However, the allowable range of CFA to be used for concrete making is 3.8 to 6.34 % beyond which compressive strength reduces.

scholarly journals Strength Characteristics of Groundnut Leaf/Stem Ash (GLSA) Concrete

2016 ◽  
Vol 24 (3) ◽  
pp. 36-43
Author(s):  
O. W. Oseni ◽  
M. T. Audu
Keyword(s):  
Compressive Strength ◽  
Strength Properties ◽  
Strength Characteristics ◽  
Partial Replacement ◽  
Structural Elements ◽  
Cement Ratio ◽  
Water Cement Ratio ◽  
Coarse Aggregates ◽  
Flow Test ◽  
Pozzolanic Properties

Abstract The compressive strength properties of concrete are substantial factors in the design and construction of concrete structures. Compressive strength directly affects the degree to which the concrete can be able to carry a load over time. These changes are complemented by deflections, cracks etc., in the structural elements of concrete. This research investigated the effect of groundnut leaf/stem ash (GLSA) on the compressive strength of concrete at 0%, 5 %, 10 % and 15 % replacements of cement. The effect of the water-cement ratio on properties such as the compressive strength, slump, flow and workability properties of groundnut leaf/stem ash (GLSA) mixes with OPC were evaluated to determine whether they are acceptable for use in concrete structural elements. A normal concrete mix with cement at 100 % (i.e., GLSA at 0%) with concrete grade C25 that can attain an average strength of 25 N/mm2 at 28 days was used as a control at design water-cement ratios of 0.65 and grading of (0.5-32) mm from fine to coarse aggregates was tested for: (1) compressive strength, and the (2) slump and flow Test. The results and observations showed that the concrete mixes from GLSA at 5 – 15 % ratios exhibit: pozzolanic properties and GLSA could be used as a partial replacement for cement at these percentage mix ratios compared with the control concrete; an increase in the water-cement ratio showed a significant decrease in the compressive strength and an increase in workability. Therefore, it is important that all concrete mixes exude an acceptably designed water-cement ratio for compressive strength characteristics for use in structures, water-cement ratio is a significant factor.

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