scholarly journals HIGH PERFORMANCE CONCRETE HAVING SILICA FUME AND METAKAOLIN AS A LIMITED REPLACEMENT OF CEMENT

2020 ◽  
Vol 15 (10) ◽  
Author(s):  
Adeed Khan
Keyword(s):  
Compressive Strength ◽  
Acid Solution ◽  
Sulphuric Acid ◽  
Silica Fume ◽  
High Performance Concrete ◽  
Cementitious Materials ◽  
Sulphuric Acid Solution ◽  
Supplementary Cementitious Materials ◽  
Cement Replacement ◽  
Concrete Cylinder

The reason for this investigation is to create HPC using locally accessible ingredients in Pakistan. The trial study incorporates the utilization of silica fume and Metakaolin mostly. The mixture of preliminaries is made utilizing various volumes of the local supplementary cementitious materials SCM and aggregates to deliver HPC. Different tests are carried out, for example, compressive strength, Rapid chloride Penetration test and Concrete cured in dilute sulphuric acid solution are assessed. The water to cement proportion was kept as .5. Every concrete samples have 0, 5, 10, 15 and 20 percent cement replacing with metakaolin and silica fume halfway. The compression strength tests are done on 28 and 90 days of cured specimens. The rapid chloride permeability test and compressive strength on the concrete cylinder when place in dilute sulphuric acid solution is done after 28 days. The outcomes appeared by utilizing MK and SF in concrete improves the mechanical properties of the concrete with different degrees up to some level. The compressive quality of the concrete cylinder is maxed on 15% cement replacing with SCM. At 5% MK and SF cement replacement the strength of the concrete samples cured in dilute H2SO4 after 28 days shows rising in the result and its strength decreases at 10% cement replacement with SCMs than its strength increased again and gives max compressive strength with 15% replacement then strength reduces again at 20% cement additional with MK and SF moderately. The charge passing rate is maxed for normal concrete samples of RCPT. There is an inverse relationship between the charge passage and cement replacement. The Charge passage is decreased by increasing the quantity of cement additional with SCMs. 20% cement additional has the least charge level and is the best mix among all.

scholarly journals The effect of Vietnam’s nano-silica on mechanical properties of high-performance concrete

2021 ◽  
Vol 72 (1) ◽  
pp. 76-83
Author(s):  
Lam Le Hong ◽  
Lam Dao Duy ◽  
Huu Pham Duy
Keyword(s):  
Compressive Strength ◽  
Silica Fume ◽  
High Performance ◽  
High Performance Concrete ◽  
Cementitious Materials ◽  
Supplementary Cementitious Materials ◽  
Nano Silica ◽  
Nano Sio2 ◽  
Curing Period ◽  
Compressive Strength Test

The demand for High Performance Concrete (HPC) is steadily increasing with massive developments. Conventionally, it is possible to use industrial products such as silica fume (SF), fly ash, as supplementary cementitious materials (SCM), to enhance the attributes of HPC. In recent years, nano-silica (NS) is used as an additive in added mainly to fill up the deviation arises with the addition of SF for HPC. This study aims to optimize the proportion of NS (produced in Vietnam) in the mixture used for fabricating 70 MPa high-performance concrete. SiO2 powder with particle size from 10 to 15 nm were used for mixing. A series of compressive strength test of HPC with nano-SiO2 varied from 0 to 2.8 percent of total of all binders (0%, 1.2%, 2%, 2.8%), and the fixed percentage of silica fume at 8% were proposed. Results show compressive strength increases with the increase of nano-SiO2, but this increase stops after reaching 2%. And at day 28 of the curing period, only concrete mixture containing of 8% silica fume and 2% nano-SiO2, had the highest compressive strength.

scholarly journals Study of Hydration and Microstructure of Mortar Containing Coral Sand Powder Blended with SCMs

Materials ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 4248
Author(s):  
Xingxing Li ◽  
Ying Ma ◽  
Xiaodong Shen ◽  
Ya Zhong ◽  
Yuwei Li
Keyword(s):  
Compressive Strength ◽  
Portland Cement ◽  
Silica Fume ◽  
Dilution Effect ◽  
Cementitious Materials ◽  
Supplementary Cementitious Materials ◽  
Limestone Powder ◽  
Chemical Effect ◽  
Granulated Blast Furnace Slag ◽  
Coral Sand

The utilization of coral waste is an economical way of using concrete in coastal and offshore constructions. Coral waste with more than 96% CaCO3 can be ground to fines and combined with supplementary cementitious materials (SCMs) such as fly ash, silica fume, granulated blast furnace slag in replacing Portland cement to promote the properties of cement concrete. The effects of coral sand powder (CSP) compared to limestone powder (LSP) blended with SCMs on hydration and microstructure of mortar were investigated. The result shows CSP has higher activity than LSP when participating in the chemical reaction. The chemical effect among CSP, SCMs, and ordinary Portland cement (OPC) results in the appearance of the third hydration peak, facilitating the production of carboaluminate. CSP-SCMs mortar has smaller interconnected pores on account of the porous character of CSP as well as the filler and chemical effect. The dilution effect of CSP leads to the reduction of compressive strength of OPC-CSP and OPC-CSP-SCMs mortars. The synergic effects of CSP with slag and silica fume facilitate the development of compressive strength and lead to a compacted isolation and transfer zone (ITZ) in mortar.

scholarly journals The Compressive Strength of High-Performance Concrete and Ultrahigh-Performance

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
E. H. Kadri ◽  
S. Aggoun ◽  
S. Kenai ◽  
A. Kaci
Keyword(s):  
Experimental Data ◽  
Compressive Strength ◽  
Silica Fume ◽  
High Performance ◽  
High Performance Concrete ◽  
Cementitious Materials ◽  
Strength Gain ◽  
Proposed Model ◽  
Partial Cement Replacement ◽  
Better Than

The compressive strength of silica fume concretes was investigated at low water-cementitious materials ratios with a naphthalene sulphonate superplasticizer. The results show that partial cement replacement up to 20% produce, higher compressive strengths than control concretes, nevertheless the strength gain is less than 15%. In this paper we propose a model to evaluate the compressive strength of silica fume concrete at any time. The model is related to the water-cementitious materials and silica-cement ratios. Taking into account the author's and other researchers’ experimental data, the accuracy of the proposed model is better than 5%.

scholarly journals Production of Ultra-High-Performance Concrete with Low Energy Consumption and Carbon Footprint Using Supplementary Cementitious Materials Instead of Silica Fume: A Review

Energies ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 8291
Author(s):  
Mays A. Hamad ◽  
Mohammed Nasr ◽  
Ali Shubbar ◽  
Zainab Al-Khafaji ◽  
Zainab Al Masoodi ◽  
...  
Keyword(s):  
Energy Consumption ◽  
Silica Fume ◽  
High Performance ◽  
High Performance Concrete ◽  
Cementitious Materials ◽  
Supplementary Cementitious Materials ◽  
Ultra High Performance Concrete ◽  
Cement Production ◽  
Granulated Blast Furnace Slag ◽  
The Impact

The increase in cement production as a result of growing demand in the construction sector means an increase in energy consumption and CO2 emissions. These emissions are estimated at 7% of the global production of CO2. Ultra-high-performance concrete (UHPC) has excellent mechanical and durability characteristics. Nevertheless, it is costly and affects the environment due to its high amount of cement, which may reach 800–1000 kg/m3. In order to reduce the cement content, silica fume (SF) was utilized as a partial alternative to cement in the production of UHPC. Nevertheless, SF is very expensive. Therefore, the researchers investigated the use of supplementary cementitious materials cheaper than SF. Very limited review investigates addressed the impact of such materials on different properties of UHPC in comparison to that of SF. Thus, this study aims to summarize the effectiveness of using some common supplementary cementitious materials, including fly ashes (FA), ground granulated blast furnace slag (GGBS), metakaolin (MK) and rice husk ashes (RHA) in the manufacturing of UHPC, and comparing the performance of each material with that of SF. The comparison among these substances was also discussed. It has been found that RHA is considered a successful alternative to SF to produce UHPC with similar or even higher properties than SF. Moreover, FA, GGBS and MK can be utilized in combination with SF (as a partial substitute of SF) as a result of having less pozzolanic activity than SF.

scholarly journals TINJAUAN PENAMBAHAN ADITIF MINERAL ABU TERBANG TERHADAP KETAHANAN BETON PADA LINGKUNGAN AGRESI SULFAT

2017 ◽  
Vol 1 (2) ◽  
Author(s):  
Ernawati Sri Sunarsih
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Acid Solution ◽  
Sulphuric Acid ◽  
Sulphuric Acid Solution ◽  
Strength Degradation ◽  
Acid Solutions ◽  
Normal Concrete ◽  
Mineral Additive ◽  
Compressive Strength Of Concrete

<p><em>The research aims to determine ( 1) the increase of compressive strength of concrete with addition of fly ash to be compared to normal concrete ( 2) the resistant of normal concrete and also concrete with fly ash mineral additive in 2%, 5% and 7% sulphuric acid solutions, and ( 3) the resitant of concrete with fly ash mineral additive with the increase of concentration of sulphuric acid solution in comparing normal concrete.</em></p><p><em>The method employed in this research was experimental method, by preparing the test object constituting the concrete cylinder with </em><em>Æ</em><em> 150 mm and 300 mm height for the compressive strength test. With the percentage of fly ash addition are 0%, 20%, 30% and 40% from requirement cement and qualities of designed concrete is 22,5 MPa. Amount of object test to the each condition is 4. To know concrete resistant in sulphate aggression environment, hence conducted by immersied of concrete in sulphuric acid solutions with concentration 2%, 5% and 7% during 30 days.</em></p><p><em>From the research, it can be found that: ( 1) the addition of fly ash into fresh concrete will improve compressive strength of concrete. At addition fly ash 20% from requirement cement, compressive strength of  concrete increase 23,39%. For the addition of fly ash 30% and 40%, the increase of compressive strength concrete were 21,54 % and 0,31%. While in optimum percentage of fly ash addition is 23,46% (2) the immersied concrete in sulphuric acid solution result degradation compressive strength of concrete. At the same concentration of sulphuric acid solution, concrete with fly ash additive mineral have resistant which is better to be compared to normal concrete. This seen [at] percentage of compressive strength degradation of fly ash concrete which is smaller to be compared to normal concrete. Equally the percentage of compressive strength degradation inversely proportional with the percentage of fly ash addition ( 3) the increase of concentration of sulphuric acid solution will be result of aggression that happened at ever greater. If compared to normal concrete, concrete with fly ash in the reality more effective if used at high concentration of sulphuric acid solution. This matter can be seen from difference of percentage of compressive strength degradation ever greater at the height of concentration of sulphuric acid solution.</em></p>

scholarly journals Compressive Strength Prediction of Self-Compacting Concrete Incorporating Silica Fume Using Artificial Intelligence Methods

2018 ◽  
Vol 4 (7) ◽  
pp. 1542 ◽  
Author(s):  
Valiollah Azizifar ◽  
Milad Babajanzadeh
Keyword(s):  
Artificial Intelligence ◽  
Compressive Strength ◽  
Silica Fume ◽  
Cementitious Materials ◽  
Multivariate Adaptive Regression Splines ◽  
Supplementary Cementitious Materials ◽  
Fine Aggregate ◽  
Effective Parameters ◽  
Self Compacting Concrete ◽  
Adaptive Regression

This paper investigates the capability of utilizing Multivariate Adaptive Regression Splines (MARS) and Gene Expression Programing (GEP) methods to estimate the compressive strength of self-compacting concrete (SCC) incorporating Silica Fume (SF) as a supplementary cementitious materials. In this regards, a large experimental test database was assembled from several published literature, and it was applied to train and test the two models proposed in this paper using the mentioned artificial intelligence techniques. The data used in the proposed models are arranged in a format of seven input parameters including water, cement, fine aggregate, specimen age, coarse aggregate, silica fume, super-plasticizer and one output. To indicate the usefulness of the proposed techniques statistical criteria are checked out. The results testing datasets are compared to experimental results and their comparisons demonstrate that the MARS (R2=0.98 and RMSE= 3.659) and GEP (R2=0.83 and RMSE= 10.362) approaches have a strong potential to predict compressive strength of SCC incorporating silica fume with great precision. Performed sensitivity analysis to assign effective parameters on compressive strength indicates that age of specimen is the most effective variable in the mixture.

Durability of Sustainable Self-Consolidating Concrete

2018 ◽  
Vol 765 ◽  
pp. 285-289
Author(s):  
Osama Ahmed Mohamed ◽  
Waddah Al Hawat ◽  
Omar Fawwaz Najm
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Silica Fume ◽  
Cementitious Materials ◽  
Chloride Penetration ◽  
Supplementary Cementitious Materials ◽  
Test Results ◽  
Self Consolidating Concrete ◽  
Human Footprint ◽  
Granulated Blast Furnace Slag

Supplementary cementitious materials such as fly ash, silica fume and ground granulated blast furnace slag (GGBS) have been used widely to partially replace cement in producing self-consolidating concrete (SCC). The production of cement is associated with emission of significant amounts of CO2 and increases the human footprint on the environment. Fly ash, silica fume, and GGBS are recycled industrial by-products that also impart favorable fresh and hardened properties on concrete. This study aims to assess the effect of the amounts of fly ash and silica fume on strength and chloride penetration resistance of concrete. Rapid Chloride Penetration Test (RCPT) was used to assess the ability of SCC to resist ingress of chlorides into concrete. SCC mixes with different dosages of fly ash and silica fume were developed and tested at different curing ages. Test results showed that replacing 20% of cement with fly ash produced the highest compressive strength of 67.96 MPa among all fly ash-cement binary mixes. Results also showed that replacing15% of cement with silica fume produced the highest compressive strength of 95.3 MPa among fly ash-cement binary mixes. Using fly ash and silica fume consistently increased the concrete resistance to chloride penetration at the early ages. Silica fume at all dosages results in low or very low levels of chloride penetration at all curing ages of concrete.

scholarly journals Two-Year Non-Destructive Evaluation of Eco-Efficient Concrete at Ambient Temperature and after Freeze-Thaw Cycles

2021 ◽  
Vol 13 (19) ◽  
pp. 10605
Author(s):  
Mohammed A. Abed ◽  
Bassam A. Tayeh ◽  
B. H. Abu Bakar ◽  
Rita Nemes
Keyword(s):  
Compressive Strength ◽  
Ambient Temperature ◽  
High Performance Concrete ◽  
Surface Hardness ◽  
Cementitious Materials ◽  
Pulse Velocity ◽  
Recycled Concrete ◽  
Supplementary Cementitious Materials ◽  
Freeze Thaw ◽  
Non Destructive

The increasing demand for eco-efficient concrete puts pressure on the industry to innovate new alternatives for its constituent materials. Coarse recycled concrete aggregates (RA) and supplementary cementitious materials (SCMs) are considered promising substitutes for coarse natural aggregates (NA) and cement, respectively. Using destructive and non-destructive testing methods, the present work aims to evaluate the effect of RA and different types of waste SCMs on the long-term performance of self-compacting high-performance concrete (SCHPC). Twenty-one mixes that were prepared with a 0.35 water-to-binder ratio were tested for their compressive strength, surface hardness, and ultrasonic pulse velocity. These tests were conducted over a two-year period at ambient temperature and again after exposure to up to 150 freeze–thaw cycles. Study findings demonstrated the possibility of developing eco-efficient SCHPC mixes using RA and waste SCMs. In addition, correlations have been introduced for predicting the compressive strength of SCHPC.

Properties of Mortar Incorporating Ground Dune Sand as Cement Replacement Material

2014 ◽  
Vol 925 ◽  
pp. 334-338
Author(s):  
Omer Abdalla Alawad ◽  
Abdulrahman Alhoziamy ◽  
Mohd Saleh Jaafar ◽  
Abdulaziz Al-Negheimish ◽  
Farah Noor Abdul Aziz
Keyword(s):  
Compressive Strength ◽  
Portland Cement ◽  
Drying Shrinkage ◽  
Cementitious Materials ◽  
Sulfate Attack ◽  
Supplementary Cementitious Materials ◽  
Replacement Level ◽  
Dune Sand ◽  
Cement Replacement ◽  
Autoclave Curing

Supplementary cementitious materials provide economic and environmental advantages in concrete industry. In this study, natural ground dune sand (GDS) was used as cement replacement material to fabricate mortar specimens. Ordinary Portland cement was replaced by GDS at five levels of replacement (0, 10, 20, 30, and 40 %) by weight. The cast mortar specimens were cured under normal and autoclave curing conditions. Compressive strength, drying shrinkage and resistance to sulfate attack were investigated. Results showed that the compressive strength under normal curing decreased as the level of replacement increased. However, under autoclave curing compressive strength increased as the content of GDS increased with 30% being the optimum replacement level. Autoclave curing decreased the drying shrinkage of plain and GDS blended mixtures by about 70% compared to control mixture cured under normal curing. Up to 270 days, no sulfate attack was observed on the GDS blended mixtures regardless of the replacement level. The use of GDS to reduce the Portland cement consumption can have a significant impact on the sustainability and economy of concrete construction.

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