scholarly journals Assessment of Longstanding Effects of Fly Ash and Silica Fume on the Compressive Strength of Concrete Using Extreme Learning Machine and Artificial Neural Network

2021 ◽  
Vol 5 (1) ◽  
pp. 50
Author(s):  
Mahdi Shariati ◽  
Danial Jahed Armaghani ◽  
Manoj Khandelwal ◽  
Jian Zhou ◽  
Arameh Eyvaziyan ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Extreme Learning Machine ◽  
Silica Fume ◽  
Cementitious Material ◽  
Short Term ◽  
Replacement Ratio ◽  
Compressive Strength Of Concrete ◽  
Artificial Neural ◽  
Learning Machine

Compressive Strength (CS) is an important mechanical feature of concrete taken as an essential factor in construction. The current study has investigated the effect of fly ash and silica fume replacement content on the strength of concrete through Artificial Neural Networks (ANNs) and Extreme Learning Machine (ELM). In this study, different ratios of fly ash with (out) extra quantity of silica fume have been tested. Water cement (w/c) ratio varies during the test. Eight input parameters including Total Cementitious Material (TCM), Silica Fume (SF) replacement ratio, coarse aggregate (ca), fly ash (FA) replacement ratio, Sewage Sludge Ash (SSA) as a combination of cement and fine aggregate replacement, water-cement ratio, High Ratio Water Reducing Agent (HRWRA) and Age of Samples (AS) and one output parameter as the CS of concrete have been investigated through ANN and ELM. Up to now, numerous experimental studies have been used to analyze the compressive strength of concrete while retrofitted with fly ash or silica fume, however, the novelty of this study is in its use of AI models (ELM, ANN). The models have been developed and their outcomes were compared through six statistical indicators (MAE, RMSE, RRMSE, WI, RMAE and R2). Subsequently, both methods were shown as reliable tools for assessing the influence of cementitious material on compressive strength of concrete, however, ANN remarkably was better than ELM. As a result, FA showed less contribution to the strength of concrete at short times, but much at later ages. As a result, the enhanced influence of low amount of SF on CS was not significant. Adding fly ash has reduced the compressive strength in short term, but increased the compressive strength in long term. Adding silica fume raises the strength in short term, but decreases the strength in longterm. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium provided the original work is properly cited.

scholarly journals Research on Mechanical Performance & Behaviour of Geopolymer Concrete Subjected to Elevated Temperatures

2019 ◽  
Vol 8 (2S8) ◽  
pp. 883-887
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Silica Fume ◽  
Elevated Temperatures ◽  
Mechanical Performance ◽  
Geopolymer Concrete ◽  
Sem Images ◽  
Before And After ◽  
Alkaline Conditions ◽  
Compressive Strength Of Concrete

The investigative studies on mechanical performance & behaviour, of Geopolymer Concrete (GPC) before and after the exposure to elevated temperatures (of 200 0 C -1000 0 C with an increment of 100 0 C). Indicate that the GPC Specimens Exhibited better Compressive strength at higher temperatures than that of those made by regular OPC Concrete with M30 Grade. The chronological changes in the geopolymeric structure upon exposure to these temperatures and their reflections on the thermal behaviour have also been explored. The SEM images indicate GPC produced by fly ash , metakaolin and silica fume, under alkaline conditions form Mineral binders that are not only non-flammable and but are also non-combustible resins and binders. Further the Observations drawn disclose that the mass and compressive strength of concrete gets reduced with increase in temperatures.

On Effects of Fly Ash as a Partial Replacement of Cement on Concrete Strength

2012 ◽  
Vol 204-208 ◽  
pp. 3970-3973
Author(s):  
Reagan J. Case ◽  
Kai Duan ◽  
Thuraichamy G. Suntharavadivel
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Concrete Strength ◽  
Cementitious Materials ◽  
Partial Replacement ◽  
Replacement Ratio ◽  
Interface Reactions ◽  
Compressive Strength Of Concrete ◽  
Interface Bonding Strength ◽  
Large Research

As a part of a large research program aiming at the cementitious materials containing recycled materials at Central Queensland University – Australia, the current paper presents the preliminary results of a study on the effects of fly ash, which is used to replace cement in concrete, on the concrete compressive strength. For this purpose, systematic experiments have been carried out to investigate the influences of fly ash ratio and age. The compressive strength of concrete specimens with replacement ratios of 15%, 30% and 45%, and aged 7 and 28 days are measured and are compared with those of the concrete specimens without fly ash at the same ages. The results demonstrate that the strength of fly ash containing concrete improves more slowly but more strongly with aging, than their fly ash free counterparts, and an optimum fly ash replacement ratio exists where the maximum compressive strength of fly ash containing concrete can be achieved, and the maximum strength for the specimens aged 28 days and above is higher that of fly ash free concrete. Furthermore, the observation strength behaviours are analysed and discussed in terms of the influences of fly ash on interface reactions and interface bonding strength.

Dry Shrinkage and Compressive Strength of Blended Cement Pastes with Fly Ash and Silica Fume

2012 ◽  
Vol 535-537 ◽  
pp. 1735-1738 ◽  
Author(s):  
Yan Li ◽  
Dao Sheng Sun ◽  
Xiu Sheng Wu ◽  
Ai Guo Wang ◽  
Wei Xu ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Silica Fume ◽  
Cement Paste ◽  
Blended Cement ◽  
Drying Shrinkage ◽  
Cementitious Material ◽  
Strength Increase ◽  
Cement Pastes ◽  
Dry Shrinkage

This paper reports the drying shrinkage and compressive strength results of cement pastes with fly ash and silica fume. In this study, Portland cement (PC) was used as the basic cementitious material. Fly ash (FA) and silica fume (SF) were used as cement replacement materials at levels of 0%, 5%, 10%, and 15% , 40%, 35%, 25%, and 15% by weight of the total cementitious material, respectively. The water/cement (PC + FA + SF) ratios (w/c) was 0.28 by weight. The samples produced from fresh pastes were demoulded after a day; then they were cured at 20 ±1°C with 50 ± 3% relative humidity (RH) until the samples were used for drying shrinkage and compressive strength measurement at various ages. The results show that drying shrinkage and compressive strength increase with increasing SF content, and the optimum composition of blended cement pastes is the cement paste with 30% fly ash and 10% silica fume, which possesses lower drying shrinkage values than that of plain cement paste and higher early age strength than that of blended cement pastes with fly ash. Furthermore, a linear relationship is established between compressive strength and drying shrinkage. By comparing the development of compressive strength and the drying shrinkage deformations, it appears possible to predict the drying shrinkage according to the acquired compressive strength.

Effect of the Combination of Calcined Shale and Pozzolanic Materials on Compressive Strength of Concrete

2013 ◽  
Vol 723 ◽  
pp. 298-302
Author(s):  
An Cheng ◽  
Wei Ting Lin ◽  
Sao Jeng Chao ◽  
Hui Mi Hsu ◽  
Chin Cheng Huang
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Silica Fume ◽  
Water Demand ◽  
Test Results ◽  
Calcination Temperatures ◽  
Heat Treated ◽  
Compressive Strength Of Concrete ◽  
Pozzolanic Materials

This study investigated the influence of individual constituents of calcined shale or hybrid constituents of calcined shale and fly ash or silica fume on the workability and compressive strength. Calcined shale is heat treated in a kiln and then ground to a finer powder and the calcination temperatures of 800 °C were used. The test results demonstrated that the workability and compressive strength decreased with the inclusion of calcined shale increased and the compressive strength of the specimens containing calcined shale all lower than that of the control specimens. It might be due to the higher water demand and lower CaO value. However, the hybrid batches with calcined shale and fly ash or silica fume enhanced better performance on compressive strength than individual constituents of calcined shale. The combination of 10 % calcined shale and 10 % silica fume in concrete seemed to give superior compressive strength and gave the highest value in the testing series. Finally, the inclusion of calcined shale is help to reduce the emissions of CO2and revealed an ecological advantage for concrete containing a binder blend of cement and calcined shale.

scholarly journals Durability and Compressive Strength of High Cement Replacement Ratio Self-Consolidating Concrete

Buildings ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 153 ◽  
Author(s):  
Osama Mohamed
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Silica Fume ◽  
Structural Engineering ◽  
Chloride Ion ◽  
Strength Development ◽  
Replacement Ratio ◽  
Self Consolidating Concrete ◽  
Granulated Blast Furnace Slag ◽  
Chloride Penetration Resistance

This study examines durability and mechanical properties of sustainable self-consolidating concrete (SCC) in which 80% of the cement is replaced with combinations of recycled industrial by-products including fly ash, silica fume, and ground granulated blast furnace slag (GGBS). The water to binder (w/b) ratio of SCC mixes studies was maintained at 0.36. The study proposes empirical relationships to predict 28-day compressive strengths based on the results of three-day and seven-day compressive strengths. In addition, the chloride penetration resistance of the various sustainable SCC mixes was determined after three days, seven days, and 28 days of moist curing of concrete standards. It was concluded that fly ash, silica fume, and GGBS contribute favorably to enhancing strength development, fresh properties, and durability of SCC in comparison to ordinary Portland cement (OPC). The compressive strength of the sustainable SCC mixes falls within ranges suitable for structural engineering applications. Replacing cement with 15% silica fume produced a 28-day average compressive strength of 95.3 MPa, which is 44.2% higher than the control mix. Replacing cement with 15% or 20% silica fume reduced the chloride ion permeability to very low amounts compared to high permeability in a control mix.

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