Investigation of Composite Deflocculant Influence on the Properties of the Refractory Castable with Chamotte Aggregate

2014 ◽  
Vol 682 ◽  
pp. 256-260 ◽  
Author(s):  
Ina Pundienė ◽  
Irina Demidova-Buiziniene ◽  
A. Volochko
Keyword(s):  
Compressive Strength ◽  
Rheological Properties ◽  
Comparative Studies ◽  
Sodium Tripolyphosphate ◽  
Strength Properties ◽  
Cement Matrix ◽  
Hydration Products ◽  
Drying Process ◽  
Different Types ◽  
Compressive Strength Of Concrete

The influence of different types of deflocculants, PCE and sodium tripolyphosphate, on the rheological properties of the cement matrix was studied. It was established that composite deflocculant consisting of sodium tripolyphosphate and PCE Castament FS 20 provides the best rheological properties of the cement matrix and affects the composition of the hydration products. During the drying process of matrix with composite deflocculants mineral stratlingite additionally formed, which contributes to increment of strength properties. Comparative studies of refractory castable strength properties with chamotte aggregate showed that the compressive strength of concrete samples with composite deflocculants after hardening and after drying and burning is almost two times higher than the strength of samples with separate deflocculants.

scholarly journals Effects of Environmental Factors on Concrete Carbonation Depth and Compressive Strength

Materials ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 2167 ◽  
Author(s):  
Ying Chen ◽  
Peng Liu ◽  
Zhiwu Yu
Keyword(s):  
Compressive Strength ◽  
Phase Composition ◽  
Relative Humidity ◽  
Co2 Concentration ◽  
Crystal Structure Analysis ◽  
Hydration Products ◽  
Carbonation Depth ◽  
Concrete Carbonation ◽  
Before And After ◽  
Compressive Strength Of Concrete

The influence of temperature, CO2 concentration and relative humidity on the carbonation depth and compressive strength of concrete was investigated. Meanwhile, phase composition, types of hydration products and microstructure characteristics of samples before and after the carbonation were analyzed by XRD and ESEM. Research results demonstrate that temperature, CO2 concentration and relative humidity influence the carbonation depth and compressive strength of concrete significantly. There is a linear relationship between temperature and carbonation depth, as well as the compressive strength of concrete. CO2 concentration and relative humidity present a power function and a polynomial function with carbonation depth of concrete, respectively. The concrete carbonation depth increases with the increase of relative humidity and reaches the maximum value when the relative humidity is 70%. Significant differences of phase composition, hydration products and microstructure are observed before and after the carbonation. Carbonization products of samples are different with changes of temperatures (10 °C, 20 °C and 30 °C). The result of crystal structure analysis indicates that the carbonation products are mainly polyhedral spherical vaterite and aragonite.

scholarly journals Evaluations of All-in-One, Polycarboxylate-Based Superplasticizer with Viscosity Modifying Agents for the Application of Normal-Strength, High-Fluidity Concrete

2021 ◽  
Vol 11 (23) ◽  
pp. 11141
Author(s):  
Tae-Woong Kong ◽  
Hyun-Min Yang ◽  
Han-Seung Lee ◽  
Chang-Bok Yoon
Keyword(s):  
Compressive Strength ◽  
Rheological Properties ◽  
Yield Stress ◽  
Lower Yield ◽  
Lower Yield Stress ◽  
Slump Flow ◽  
Different Types ◽  
Long Time ◽  
Normal Strength ◽  
Physical Phenomena

High fluidity concrete exhibits an excellent self-compacting property. However, the application of typical high-fluidity concrete is limited in the normal strength range (18~35 MPa) due to the large amount of binder. Therefore, it is important to solve these problems by adding a viscosity modifying agent (VMA) with a superplasticizer (PCE), which helps to improve the fluidity of the concrete. In addition, the rheology and stability of the concrete with VMA can be improved by preventing bleeding and segregation issues. Current studies focused on the physical phenomena of concrete such as the fluidity, rheological properties, and compressive strength of normal-strength, high-fluidity concrete (NSHFC) with different types of a polycarboxylate-based superplasticizer (NPCE). The obtained results suggested that the combinations of all-in-one polycarboxylate-based superplasticizers (NPCE) did not cause any cohesion or sedimentation even stored for a long time. The combination of three types of VMA showed the best fluidity (initial slump flow of 595~630 mm) without any segregation and bleeding, and the compressive strength at 28 days was also found to be the highest: 34–37 MPa. From these results, the combination of PCE (2.0%) + HPMC (0.3%) + WG (0.1%) + ST (0.1%) showed an 18% higher plastic viscosity and -4.4% lower yield stress than Plain.

scholarly journals Assessment of Workability and Compressive Strength of Rice Husk Ash-Blended Palm Kernel Shell Concrete

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
K. O. Oriola
Keyword(s):  
Compressive Strength ◽  
Rice Husk ◽  
Rice Husk Ash ◽  
Construction Materials ◽  
Palm Kernel ◽  
Lightweight Aggregate ◽  
Strength Properties ◽  
Lightweight Aggregate Concrete ◽  
Palm Kernel Shell ◽  
Compressive Strength Of Concrete

The evaluation of agro-industrial by-products as alternative construction materials is becoming more significant as the demand for environmentally friendly construction materials increases. In this study, the workability and compressive strength of concrete produced by combining Palm Kernel Shell (PKS) and Rice Husk Ash (RHA) was investigated. Concrete mixes using a fixed content of 15% RHA as replacement for cement and 20, 40, 60, 80 and 100% PKS as replacement for crushed granite by volume with the mix ratios of 1:1½:3, 1:2:4 and 1:3:6 were produced. The water-to-cement ratios of 0.5, 0.6 and 0.7 were used for the respective mix ratios. Concrete without PKS and RHA served as control mix. The fresh concrete workability was evaluated through slump test. The concrete hardened properties determined were the density and compressive strength. The results indicated that the workability and density of PKSC were lower than control concrete, and they decreased as the PKS content in each mix ratio was increased. The compressive strength of concrete at 90 days decreased from 27.8-13.1 N/mm2, 23.8-8.9 N/mm2and 20.6-7.6 for 1:1½:3, 1:2:4 and 1:3:6, respectively as the substitution level of PKS increased from 0-100%. However, the compressive strength of concrete increased with curing age and the gain in strength of concrete containing RHA and PKSC were higher than the control at the later age. The concrete containing 15% RHA with up to 40% PKS for 1:1½:3 and 20% PKS for 1:2:4 mix ratios satisfied the minimum strength requirements for structural lightweight aggregate concrete (SLWAC) stipulated by the relevant standards. It can be concluded that the addition of 15% RHA is effective in improving the strength properties of PKSC for eco-friendly SLWAC production..

The Effect of Different Curing Conditions on Compressive Strength of Concrete

2017 ◽  
Vol 60 (3) ◽  
pp. 147-153
Author(s):  
Muhammad Arslan ◽  
Muhammad Asif Saleem ◽  
Maria Yaqub ◽  
Muhammad Saleem Khan
Keyword(s):  
Compressive Strength ◽  
Research Work ◽  
Concrete Structures ◽  
Strength Test ◽  
The Other ◽  
Cylindrical Shape ◽  
Curing Conditions ◽  
Compressive Strength Test ◽  
Different Types ◽  
Compressive Strength Of Concrete

The focus of this research work was to analyse the effect of different types of curing oncompressive strength of concrete structures. For this purpose, 54 test specimens of cylindrical shape wereprepared. These specimens were cured with different methods and were tested on different age days toanalyse the effect of curing on compressive strength. Test specimens cured with conventional water curingmethod gives the highest results as compared to the other adopted methods.

scholarly journals Isothermal Drying Process and its Effect on Compressive Strength of Concrete in Multiscale

2019 ◽  
Vol 9 (19) ◽  
pp. 4015
Author(s):  
Du ◽  
Li ◽  
Tong ◽  
Li ◽  
Liu
Keyword(s):  
Compressive Strength ◽  
Pore Diameter ◽  
Strengthening Effect ◽  
Drying Process ◽  
Average Pore ◽  
Competition Result ◽  
Compressive Strength Of Concrete ◽  
Paste Content ◽  
Isothermal Drying ◽  
Microstructural Studies

Drying could change the microstructure of cement-based materials and inevitably affect their mechanical properties. The isothermal drying process of concrete at three scales and its effect on compressive behavior and microstructure were investigated. The deformations of cement paste, mortar, and concrete in the drying process all exhibit the characteristics of expansion first and then shrinkage. The porosity and average pore diameter increase after drying, which is mainly attributed to the increase of pores less than 100 nm diameter for paste and to the pores within 100~1000 nm for mortar. Drying makes paste denser, while the bonding between paste and aggregate is weakened. Microstructural studies indicate that the increase in compressive strength of concrete caused by isothermal drying is the competition result between the strengthening effect and the weakening effect, and is related to the paste content.

Modified Plasters for Restoration and Finishing Works

2014 ◽  
Vol 923 ◽  
pp. 42-47 ◽  
Author(s):  
Myroslav Sanytsky ◽  
Tetiana Kropyvnytska ◽  
Roman Kotiv
Keyword(s):  
Compressive Strength ◽  
Chemical Composition ◽  
Cementitious Materials ◽  
Quality Parameters ◽  
Supplementary Cementitious Materials ◽  
Cement Matrix ◽  
Hydration Products ◽  
High Quality ◽  
Physico Chemical ◽  
White Portland Cement

The paper is devoted to the research and development of modified plasters for restoration and finishing works based on decorative multicomponent cements containing white Portland cement and supplementary cementitious materials (silica fume, metakaolin and fine ground limestone). This cements are similar to Roman cement by their chemical composition. The use of optimal granulometry of decorative multicomponent cements provide directed formation of microstructure of the cement matrix with the formation of stable hydration products. Compositions of modified plasters by the criterions of workability and compressive strength were designed. Physico-chemical modification of plaster by complex air-entraining admixture allows to obtain high-quality modified plasters with improved quality parameters.

scholarly journals Effects of HDPE Plastic Waste Aggregate on the Properties of Concrete

2021 ◽  
Vol 9 (10) ◽  
pp. 519-524
Author(s):  
Shakir Hussain
Keyword(s):  
Compressive Strength ◽  
Coarse Aggregate ◽  
Cost Effective ◽  
Strength Properties ◽  
Cement Matrix ◽  
Polymer Concrete ◽  
Hardened Concrete ◽  
Polymer Waste ◽  
Wide Range ◽  
Polymer Wastes

Abstract: Polymer waste volumes have surged in recent years as a result of growing industrialization and fast improvements in living standards. In Malaysia, the majority of polymer waste is discarded rather than recycled. This circumstance results in major issues such as waste of natural resources and pollution of the environment. Polymer products, such as synthetic fibres, plastics, and rubber, are petrochemical compounds that disintegrate slowly in nature. Even after a long amount of time, plastic materials are not easily biodegradable. In reality, a wide range of waste materials can be used as a cement matrix inert. For the manufacture of the polymer concrete, trash bag plastics were employed as polymer wastes HDPE in this study (PC). The purpose of this research is to investigate the characteristics and characterisation of polymer HDPE as a coarse aggregate replacement in concrete. Temperatures of 160°C, 170°C, 180°C, 190°C, and 200°C were used in the heating procedure. By volumetric approach, five compositions of coarse aggregate with varied crushed stone: HDPE waste ratios of 0:100, 15:85, 30:70, 45:55, and 60:40 were utilised. The use of polymerwaste as coarse aggregate in traditional concrete was examined. With fresh and hardened concrete tests, the effects of polymer wastes on the workability and strength of the concrete were investigated. After 28 days, the compressive strength of the PCwas determined to be suitable for nonstructural use. The findings of the cost research revealed that the PC is more cost effective than traditional concrete. Keywords: Polymer Wastes HDPE; Coarse Aggregate; Compressive Strength; Properties

scholarly journals Strength Properties of Concrete with Aggregates from Alternate Sources

2019 ◽  
Vol 9 (1) ◽  
pp. 4066-4069
Keyword(s):  
Compressive Strength ◽  
Glass Powder ◽  
Coarse Aggregate ◽  
Environmental Issues ◽  
Casting Process ◽  
Strength Properties ◽  
Metal Casting ◽  
Fine Aggregate ◽  
Foundry Sand ◽  
Compressive Strength Of Concrete

Aggregates used in concrete are fast depleting natural resource and the quarrying of which is causing environmental issues. Hence, the use of aggregate from alternate sources such as from waste discarded glass, from foundry sand discarded after metal casting process and sea shells is investigated. Compressive strength of concrete with glass powder, foundry sand and sea shell is studied individually. Concrete is cast with glass powder and foundry sand as 5%, 10%, 15% and 20% replacement of fine aggregate and with sea shell as 5%, 10%, 15% and 20% replacement of coarse aggregate individually. It is observed that compressive strength of concrete decreases with glass powder, foundry sand, and sea shell. Fine aggregate replaced by 10% glass powder, 10%, foundry sand and coarse aggregate replaced by 10% sea shell have the least decrease in strength when compared to control concrete mix.

scholarly journals The influence of different type of aggregate, fly ash and fiber-reinforced polymer on splitting resistance in pretensioned concrete railroad ties

2021 ◽  
Vol 27 (4) ◽  
pp. 135-140
Author(s):  
Adrijana Savić ◽  
Robert Peterman
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Fiber Reinforced Polymer ◽  
Concrete Mixture ◽  
Fiber Reinforced ◽  
Reinforced Polymer ◽  
Pretensioned Concrete ◽  
Edge Distance ◽  
Different Types ◽  
Compressive Strength Of Concrete

This research evaluates the influence of the different types of concrete mixture, using a shallow type of indentation of wire, having the different edge distance and compressive strength of concrete on splitting resistance in pretensioned concrete railroad sleepers. The investigated compressive strength of concrete was 4500psi. The research was experimental, and the part of this research was formally adapted in Arema StandardsforRailwayEngineering Chapter 30 section 4.2.4.

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