modifying the microstructure of concrete to decrease

Modifying the Microstructure of Concrete to Decrease ...

Jul 25, 2016  Modifying the Microstructure of Concrete to Decrease Emissions. by Sarah McGuire. July 25, 2016. Photo: Stuart Darsch. An MIT-led team has defined the nanoscale forces that control how particles pack together during the development of cement “paste,” the material that holds together concrete and causes that ubiquitous construction material ...

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Microstructure of Concrete IntechOpen

Oct 05, 2016  Figure 1. Left: polished section of concrete specimen. Right: microstructure of a hydrated cement paste [1].Concrete with superior properties such as high compressive strength and excellent durability can be produced by taking into account the following: (i) optimizing particle size distribution to obtain high density; (ii) using water reducer agents to reduce water/cement (w/c) ratio;

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The Microstructure of Concrete - University of Cape Town

the microstructure of cement and concrete will be discussed in more detail. optical microscopy has been widely used in the study of cement and concrete.T The use of suitable etchants makes it pQlsible to study the distribution of anhydrous phases in clinker and cement powder.6'v In hydrated pastes and concrete tiere is

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Modified - IJCSEIERD - MATERIALS TO IMPROVE TENSILE ...

Concrete is defined as a composite material, which is weak in tension and strong in compression. It becomes very essential to improve the tensile strength of concrete at micro level, to make durable concrete structures. Researchers from various countries are using various materials to improve the mechanical properties of concrete at micro and nano

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Study on Properties of Modified Reactive Powder Concrete

microstructure is obtained by means of heat treatment i.e. hot water curing. Heat-treating is performed after the concrete has set, by simply heating at ambient temperature. Heat-treating at 90°C substantially accelerates the pozzolanic reaction, while modifying the microstructure of the hydrates which have formed. However

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Modified - IJCSEIERD - MATERIALS TO IMPROVE TENSILE ...

Concrete is defined as a composite material, which is weak in tension and strong in compression. It becomes very essential to improve the tensile strength of concrete at micro level, to make durable concrete structures. Researchers from various countries are using various materials to improve the mechanical properties of concrete at micro and nano

get price

Supplementary Cementitious Materials — What, why, how ...

These materials modify the microstructure of concrete and reduce its permeability thereby reducing the penetration of water and water-borne salts into concrete. Watertight concrete will reduce various forms of concrete deterioration, such as corrosion of reinforcing steel and chemical attack. Most supplementary cementitious materials can reduce ...

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Study on Properties of Modified Reactive Powder Concrete

microstructure is obtained by means of heat treatment i.e. hot water curing. Heat-treating is performed after the concrete has set, by simply heating at ambient temperature. Heat-treating at 90°C substantially accelerates the pozzolanic reaction, while modifying the microstructure of the hydrates which have formed. However

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Microstructural analysis of recycled concrete using X-ray ...

Mar 01, 2016  The recycled aggregate can modify the effective content of water in the concrete mixtures, increase the mixing time, and affect the properties of fresh and hardened concrete due to the high water absorption rate , , , . The microstructure of the RC can also be strongly influenced by the water absorption and by the way this water absorption is ...

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Microstructural Characterization of Concrete Prepared with ...

Concrete is a composite mixture formed from cement, aggregates, water, and eventually admixtures or partial cement replacement materials. Setting and hardening of concrete occurs by a hydration reaction between the oxides in the cement and water, rendering a complex microstructure, which determines the properties of the hardened material.

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Effect of nano-CaCO3 and nano-SiO2 on improving the ...

May 30, 2020  In this study, nano-CaCO 3 and nano-SiO 2 were effectively employed to reduce the permeability of carbon fibre-reinforced concrete (CFRC) with a water-cement ratio (W/C) of 0.3 and 0.4. Further, the mechanism of these nanomaterials when modifying the microstructure of CFRC is discussed. It was found that the addition of carbon fibre demonstrated a decrease and increase effect

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Effect of Superplasticizer and NaOH Molarity on ...

decrease in workability of these concrete samples were observed with ... microstructure of concrete. This paper presents the test results ... Viscosity Modifying Admixture (VMA) gives more possibilities of controlling segregation (stability) and homogeneity of the mix [20]. The amount of SP used was in

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Mechanical and permeability properties of polymer-modified ...

Sep 01, 2020  When OSW is used to modify concrete, the compressive strength of PMC decreased slightly or even increased. In addition, although the strength of concrete is reduced by adding FA, the strength loss rate of the PMC specimens with FA is significantly reduced. Download : Download high-res image (509KB) Download : Download full-size image; Fig. 2.

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(PDF) Effect of Addition of Combination of Admixtures on ...

Viscosity modifying admixture:A viscosity modifying admixture called Structuro 485 was used to induce the flow without segregation. It was used at the rate of 0.30% weight of binder (cement + flyash) Superplasticizer:A high performance concrete superplasticizer Structuro 100 based on modified polycarboxylic ether was used.

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3-D printing of concrete: Beyond horizons - ScienceDirect

Jul 01, 2020  The Virtual Cement and Concrete Testing Laboratory (VCCTL) software developed by NIST is an example of computational materials science tools that allow a user to model microstructure, simulate hydration, and calculate physical properties and can be used in the development, testing, and quality control of cement and concrete materials.

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Purdue e-Pubs - International Conference on Durability of ...

Self-Compacting Concrete (SCC) can incorporate different types of Supplementary cementitious materials (SCM), as filler and other active mineral additions, to increase the amount of paste without increasing the amount of cement. SCM modify the SCC hardened microstructure due to the filler effect, the seeding effect as nucleation points for hydration products and the pozzolanic effect in the ...

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Effect of nano-strengthening on the properties and ...

Influence of nano-strengthening immersion on the properties of recycled aggregate (RA) and recycled aggregate concrete (RAC) and the microstructure of interfacial transition zones (ITZs) between mortar and aggregate were studied in this paper. Results showed that nano-strengthening immersion was helpful to reduce the crushing value and total pore area of RA, to significantly improve the ...

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Difference between Self Compacting and Normal Concrete ...

The plastic settlement is formed in the concrete above the reinforcement in NCC structures. The use of viscosity modifying agent and increased powdered content in SCC helps to decrease the risk of plastic settlement cracks. Higher flowability and plastic settlement in SCC prevents the occurrence of plastic settlement that is common in NCC.

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Designing climate-friendly concrete, from the nanoscale up ...

Jul 21, 2016  By controlling those forces, the researchers will now be able to modify the microstructure of the hardened cement paste, reducing pores and other sources of weakness to make concrete stronger, stiffer, more fracture-resistant, and longer-lasting.

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Study on Properties of Modified Reactive Powder Concrete

microstructure is obtained by means of heat treatment i.e. hot water curing. Heat-treating is performed after the concrete has set, by simply heating at ambient temperature. Heat-treating at 90°C substantially accelerates the pozzolanic reaction, while modifying the microstructure of the hydrates which have formed. However

get price

Purdue e-Pubs - International Conference on Durability of ...

Self-Compacting Concrete (SCC) can incorporate different types of Supplementary cementitious materials (SCM), as filler and other active mineral additions, to increase the amount of paste without increasing the amount of cement. SCM modify the SCC hardened microstructure due to the filler effect, the seeding effect as nucleation points for hydration products and the pozzolanic effect in the ...

get price

Supplementary Cementitious Materials — What, why, how ...

These materials modify the microstructure of concrete and reduce its permeability thereby reducing the penetration of water and water-borne salts into concrete. Watertight concrete will reduce various forms of concrete deterioration, such as corrosion of reinforcing steel and chemical attack. Most supplementary cementitious materials can reduce ...

get price

Microstructural Characterization of Concrete Prepared with ...

Concrete is a composite mixture formed from cement, aggregates, water, and eventually admixtures or partial cement replacement materials. Setting and hardening of concrete occurs by a hydration reaction between the oxides in the cement and water, rendering a complex microstructure, which determines the properties of the hardened material.

get price

Effect of Superplasticizer and NaOH Molarity on ...

decrease in workability of these concrete samples were observed with ... microstructure of concrete. This paper presents the test results ... Viscosity Modifying Admixture (VMA) gives more possibilities of controlling segregation (stability) and homogeneity of the mix [20]. The amount of SP used was in

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(PDF) CONCRETE Microstructure, Properties and Materials ...

CONCRETE Microstructure, Properties and Materials. Tin Phyo Hlaing. Pauline Santiago + 10 More. Download PDF. Download Full PDF Package. This paper. A short summary of this paper. 37 Full PDFs related to this paper. Read Paper. CONCRETE Microstructure, Properties and Materials.

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(PDF) Effect of Addition of Combination of Admixtures on ...

Viscosity modifying admixture:A viscosity modifying admixture called Structuro 485 was used to induce the flow without segregation. It was used at the rate of 0.30% weight of binder (cement + flyash) Superplasticizer:A high performance concrete superplasticizer Structuro 100 based on modified polycarboxylic ether was used.

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Experimental and microstructure study on coconut fibre ...

Sep 10, 2020  Viscosity modifying admixture (VMA) is a white coloured liquid of high viscosity used to maintain homogeneity of CFRSCC. It is essential to control the stability and cohesion of self-compacting concrete. It could reduce bleeding of SCC mixes when additives, namely fibres, were added and supplied by ASTRA Chemicals.

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Polymer Modified Concrete of Blended Cement and Natural ...

This paper deals with the effect of blended cement and natural latex copolymer to static and dynamic properties of polymer modified concrete. The polymer was used copolymer of natural latex methacrylate (KOLAM) and copolymer of natural latex styrene (KOLAS) with composition of 1%, 5%, and 10% w/w of weight of blended cement in concrete mixture.

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Difference between Self Compacting and Normal Concrete ...

The plastic settlement is formed in the concrete above the reinforcement in NCC structures. The use of viscosity modifying agent and increased powdered content in SCC helps to decrease the risk of plastic settlement cracks. Higher flowability and plastic settlement in SCC prevents the occurrence of plastic settlement that is common in NCC.

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Low Carbon Concrete - Cembureau

Concrete is already a low carbon product compared to many other common construction materials. The vast majority of cement is used as a binder in concrete; it is mixed with water and aggregates to make concrete. Various options to reduce the carbon footprint of cement are covered in the first three parallel routes presented here, but to further ...

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Microstructure Characteristics of Fly Ash Concrete with ...

Feb 21, 2018  Addition of LP to cement causes an increase of hydration at early ages inducing a high early strength, but it can reduce the long-term strength due to the dilution effect (Ghrici et al. 2007).RHA could be advantageously blended with OPC without adversely affecting the strength and permeability properties of concrete due to the pozzolanic reaction and packing effect (Ganesan et al. 2008).

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Comparative study on mechanisms for improving mechanical ...

NC can react with cement clinker and modify the microstructure of cement paste. It could accelerate the hydration process and react with C 3 S, C 3 A, and C 4 AF to form C–S–H gel and C–A–S–H gel due to the introduction of Ca 2+ , which resulted in the improvement of compressive strength in

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NUCLEAR POWER PLANT CONCRETE STRUCTURES

performance concrete (HPC) (Shah and Ahemd 1994, Neville 1996, Aitcin 1998). HPC mix is generally attributed to higher strength and durability than NSC. Improved properties of HPC is achieved by modifying the microstructure, particularly that of transition zone. Such modification

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