The effect of high fly ash content on the compressive strength of foamed concrete

2001 ◽  
Vol 31 (1) ◽  
pp. 105-112 ◽  
Author(s):  
E.P Kearsley ◽  
P.J Wainwright
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Ash Content ◽  
Foamed Concrete

scholarly journals Experiments on Foamed Concrete for the Development of Building Blocks

2020 ◽  
Vol 8 (5) ◽  
pp. 2824-2829
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Building Blocks ◽  
Ash Content ◽  
Partial Replacement ◽  
Dry Density ◽  
Load Bearing ◽  
Concrete Building ◽  
Concrete Blocks ◽  
Foamed Concrete

Foamed concrete is an innovative and versatile lightweight building material, which is a cement-based mortar consisting of at least 20% of its volume filled with air. Use of lightweight foamed concrete blocks with densities less than 1800 kg/m3 as infills will lead to the design of slender sections. Further, the thermal insulation properties of foamed concrete blocks made it more popular in construction industry. This paper discusses the development of foamed concrete building blocks for load bearing and non-load bearing structures. To make the mix more sustainable, the feasibility of fly ash as a partial replacement to cement is also explored. The variables considered for the production of foamed concrete are foam volume, water/powder (mix of cement and fly ash) ratio, fly ash content and sand/powder ratio. Analytical model is also developed for compressive strength and dry density of foamed concrete considering different variables and it is validated. Compressive strength is found to be increasing with the increase in dry density and with increase in fly ash content. Thermal conductivity is observed to be reduced by the addition of fly ash content

Physical Properties of Cement Mortar Containing Waste Ash

2015 ◽  
Vol 804 ◽  
pp. 129-132
Author(s):  
Sumrerng Rukzon ◽  
Prinya Chindaprasirt
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Rice Husk ◽  
Rice Husk Ash ◽  
Cement Mortar ◽  
Ash Content ◽  
Water Requirement ◽  
Test Results ◽  
Pozzolanic Material ◽  
Materials Used

This research studies the potential for using waste ash from industrial and agricultural by-products as a pozzolanic material. Classified fly ash (FA) and ground rice husk ash (RA) were the materials used. Water requirement, compressive strength and porosity of cement mortar were investigated. Test results indicated that FA and RA (waste ash) have a high potential to be used as a good pozzolanic material. The water requirement of mortar mix decreases with the increases in fly ash content. For ground rice husk ash (RA), the water requirement of mortar mix increases with the increases in rice husk ash content. In addition, the reduction in porosity was associated with the increase in compressive strength.

scholarly journals Biofuel Combustion Fly Ash Influence on the Properties of Concrete

2016 ◽  
Vol 7 (5) ◽  
pp. 546-550
Author(s):  
Aurelijus Daugėla ◽  
Džigita Nagrockienė ◽  
Laurynas Zarauskas
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Portland Cement ◽  
Water Absorption ◽  
Frost Resistance ◽  
Ash Content ◽  
Mineral Admixtures ◽  
Binding Agent ◽  
Materials Used ◽  
Plasticizing Admixture

Cement as the binding agent in the production of concrete can be replaced with active mineral admixtures. Biofuel combustion fly ash is one of such admixtures. Materials used for the study: Portland cement CEM I 42.5 R, sand of 0/4 fraction, gravel of 4/16 fraction, biofuel fly ash, superplasticizer, water. Six compositions of concrete were designed by replacing 0%, 5%, 10%, 15% 20%, and 25% of cement with biofuel fly ash. The article analyses the effect of biofuel fly ash content on the properties of concrete. The tests revealed that the increase of biofuel fly ash content up to 20% increases concrete density and compressive strength after 7 and 28 days of curing and decreases water absorption, with corrected water content by using plasticizing admixture. It was found that concrete where 20% of cement is replaced by biofuel ash has higher frost resistance.

High Volume Slag and Slag-Fly Ash Blended Cement Pastes Containing Nano Silica

2019 ◽  
Vol 967 ◽  
pp. 205-213
Author(s):  
Faiz U.A. Shaikh ◽  
Anwar Hosan
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Cement Paste ◽  
Ordinary Portland Cement ◽  
Blended Cement ◽  
High Volume ◽  
Ash Content ◽  
Partial Replacement ◽  
Nano Silica ◽  
Cement Pastes

This paper presents the effect of nanosilica (NS) on compressive strength and microstructure of cement paste containing high volume slag and high volume slag-fly ash blend as partial replacement of ordinary Portland cement (OPC). Results show that high volume slag (HVS) cement paste containing 60% slag exhibited about 4% higher compressive strength than control cement paste, while the HVS cement paste containing 70% slag maintained the similar compressive strength to control cement paste. However, about 9% and 37% reduction in compressive strength in HVS cement pastes is observed due to use of 80% and 90% slag, respectively. The high volume slag-fly ash (HVSFA) cement pastes containing total slag and fly ash content of 60% exhibited about 5%-16% higher compressive strength than control cement paste. However, significant reduction in compressive strength is observed in higher slag-fly ash blends with increasing in fly ash contents. Results also show that the addition of 1-4% NS improves the compressive strength of HVS cement paste containing 70% slag by about 9-24%. However, at higher slag contents of 80% and 90% this improvement is even higher e.g. 11-29% and 17-41%, respectively. The NS addition also improves the compressive strength by about 1-59% and 5-21% in high volume slag-fly ash cement pastes containing 21% fly ash+49%slag and 24% fly ash+56%slag, respectively. The thermogravimetric analysis (TGA) results confirm the reduction of calcium hydroxide (CH) in HVS/HVSFA pastes containing NS indicating the formation of additional calcium silicate hydrate (CSH) gels in the system. By combining slag, fly ash and NS in high volumes e.g. 70-80%, the carbon footprint of cement paste is reduced by 66-76% while maintains the similar compressive strength of control cement paste. Keywords: high volume slag, nanosilica, compressive strength, TGA, high volume slag-fly ash blend, CO2 emission.

Experimental Study on Workability and Strength of Green High Performance Concrete with High Volume Fly Ash

2013 ◽  
Vol 859 ◽  
pp. 52-55 ◽  
Author(s):  
Yong Qiang Ma
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Fly Ash ◽  
High Performance ◽  
High Performance Concrete ◽  
High Volume ◽  
Ash Content ◽  
Splitting Tensile Strength ◽  
Binder Ratio ◽  
Water Binder Ratio

A great deal of experiments have been carried out in this study to reveal the effect of the water-binder ratio and fly ash content on the workability and strengths of GHPC (green high performance concrete). The workability of GHPC was evaluated by slump and slump flow. The strengths include compressive strength and splitting tensile strength. The results indicate that the increase of water-binder ratio can improve the workability of GHPC, however the strengths of GHPC were decreased with the increase of water-binder ratio. When the fly ash content is lower than 40%, the increase in fly ash content has positive effect on workability of GHPC, while the workability begins to decrease after the fly ash content is more than 40%. The addition of fly ash in GHPC has adverse effect on the strengths, and there is a tendency of decrease in the compressive strength and splitting tensile strength of GHPC with the increase of fly ash content.

Fly Ash Particle Reinforced AA6061 Composites Produced by Recycling of Aluminum Chips and Fly Ash Particles

2011 ◽  
Vol 324 ◽  
pp. 38-41
Author(s):  
Recep Vatansever ◽  
Harun Mindivan ◽  
E.S. Kayali
Keyword(s):  
Mechanical Properties ◽  
Electrical Conductivity ◽  
Compressive Strength ◽  
Aluminum Alloy ◽  
Fly Ash ◽  
Hot Extrusion ◽  
Ash Content ◽  
Aluminum Powders ◽  
Aluminum Chips ◽  
Recycled Composites

In this work, the re-use of aluminum AA6061 chips and fly ash particles by solid-state processes (cryomilling, cold compaction and hot extrusion) is presented. The process was performed in following steps: comminuting of chips, cryomilling of comminuted chips, aluminum powders and fly ash particles, cold pressing-hot extrusion approach without sintering step. Comparative analysis of the recycled composites with fine and coarse granulated chips was focused on mechanical properties and correlated to microstructural features. The density and electrical conductivity of the recycled composites are lower than those of the unreinforced aluminum alloy due to the presence of fly ash particles. Regarding mechanical properties, the recycled composites with coarse granulated chips showed higher hardness and compressive strength than the recycled composites with fine granulated chips, but the compressive strength of the recycled composites with coarse granulated chips decreased with the increase of fly ash content.

Mechanical Properties of Reactive Powder Concrete Containing Fly Ash under Different Curing Regimes

2014 ◽  
Vol 597 ◽  
pp. 320-323 ◽  
Author(s):  
De Hong Wang ◽  
Yan Zhong Ju ◽  
Wen Zhong Zheng
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Fly Ash ◽  
Flexural Strength ◽  
Ash Content ◽  
Reactive Powder Concrete ◽  
Steam Curing ◽  
Cement Ratio ◽  
Reactive Powder ◽  
Curing Regimes

Mechanical properties of reactive powder concrete (RPC) containing fly ash were investigated under different curing regimes (standard and steam curing) in this study. The experimental results indicate that, flexural strength of RPC increased considerably after steam curing, compared to the standard curing. Steam curing had no significant effect on compressive strength of RPC. Increasing the fly ash content improved the flexural strength of RPC under all curing regimes considerably. The compressive strength reached a maximum (103.8MPa) when the fly to ash and cement ratio is 0.3.

Drying Shrinkage of Fly Ash Mortar Mixed with Seawater

2015 ◽  
Vol 802 ◽  
pp. 118-123 ◽  
Author(s):  
John Wilmer Bautista ◽  
John Benedict Crockett ◽  
Beatrice Ann Liu ◽  
Timothy John Obra ◽  
Cheryl Lyne Roxas
Keyword(s):  
Carbon Dioxide ◽  
Compressive Strength ◽  
Fly Ash ◽  
Carbon Dioxide Emissions ◽  
Drying Shrinkage ◽  
Water Shortage ◽  
Ash Content ◽  
Partial Substitution ◽  
Partial Replacement ◽  
Micro Cracks

Drying shrinkage in mortar produces cracks and micro-cracks which affect the durability of a structure. The effects of seawater as a substitute to freshwater and fly ash as a partial replacement for cement were investigated in this study in order to address the predicted water shortage by 2025 and the increasing carbon footprint from carbon dioxide emissions worldwide. Moreover, these materials are also more economical alternatives to freshwater and cement. Rectangular prism specimens with varying fly ash content (10%, 15%, 20%, 25%, and 30%) were cast to measure the drying shrinkage in mortar while 50-mm cube mortar specimens were prepared to determine the compressive strength. This study investigated whether the addition of fly ash and seawater reduced the drying shrinkage of mortar. From the results, it was found that mortar specimens with 20% fly ash replacement achieved the highest early and late strengths. Partial substitution of fly ash would result to shrinkage in mortar while substitution of seawater to freshwater counteracts the effects of fly ash, thus producing less shrinkage. Fly ash content between 20%-25% combined with seawater produces the least shrinkage value without compromising the minimum required compressive strength.

Effect of Fly Ash Content on Mechanical Properties of Cement-Fly Ash Stabilized Crushed Stones

2014 ◽  
Vol 548-549 ◽  
pp. 228-232 ◽  
Author(s):  
Xiao Chen ◽  
Ji Wei Liu ◽  
Ming Kai Zhou
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Fly Ash ◽  
Crack Resistance ◽  
Unconfined Compressive Strength ◽  
Resilient Modulus ◽  
Ash Content ◽  
Mechanical Parameters ◽  
Cleavage Strength ◽  
The Impact

To improve the impact of fly ash on the properties of cement-fly ash stabilized crushed stone, and promote it popularize and apply better. This paper investigated the effect of fly ash content on unconfined compressive strength, cleavage strength and resilient modulus of cement-fly ash stabilized crushed stones, and those relationships between mechanical parameters. The results showed that with increasing of the fly ash content, the unconfined compressive strength and cleavage strength increased at first, then decreased, the resilient modulus decreased, and The brittleness index increased. We can conclude that the optimal fly ash content is between 10% and 15%, and increment of fly ash content can improve its crack-resistance.

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