scholarly journals Features of the Chemical Interaction of 2-Furaldehyde and 1,3,5-Trihydroxybenzene in an Alkaline Medium to Obtain a Plasticizing Additive

2021 ◽  
Vol 5 (4) ◽  
pp. 84
Author(s):  
Valentina Anatolyevna Poluektova ◽  
Natalia Igorevna Cherkashina ◽  
Sergey Aleksandrovich Starchenko ◽  
Dmitriy Sergeevich Romanyuk
Keyword(s):  
Alkaline Medium ◽  
Dry Matter ◽  
Chemical Interaction ◽  
Uv Spectroscopy ◽  
Strength Characteristics ◽  
Optimal Dosage ◽  
Cement Ratio ◽  
Water Cement Ratio ◽  
Stretching Vibrations ◽  
Reduced Water

The paper presents data on the study of the polycondensation of 2-furaldehyde and 1,3,5-trihydroxybenzene in an alkaline medium to obtain a plasticizing additive. Results are presented on the study of the products of the separate interaction of 1,3,5-trioxybenzene and 2-furaldehyde with NaOH, and the joint polycondensation of 1,3,5-trioxybenzene with 2-furaldehyde with NaOH by UV spectroscopy. The structure of the product of the interaction of 1,3,5-trioxybenzene with 2-furaldehyde in an alkaline medium was studied by IR spectroscopy. Stronger C–H bonds appear in the IR spectrum and stretching vibrations of the C = O group are not observed, which confirms the production of a new compound. The optimal dosage of the developed plasticizing additive has been established as 0.3% of the cement mass (calculated on dry matter). The developed plasticizing additive can significantly reduce the water-cement ratio while maintaining the strength characteristics of cement compositions. In addition, when using the additive, the strength characteristics are significantly increased with a reduced water-cement ratio.

scholarly journals Strength Characteristics of Groundnut Leaf/Stem Ash (GLSA) Concrete

2016 ◽  
Vol 24 (3) ◽  
pp. 36-43
Author(s):  
O. W. Oseni ◽  
M. T. Audu
Keyword(s):  
Compressive Strength ◽  
Strength Properties ◽  
Strength Characteristics ◽  
Partial Replacement ◽  
Structural Elements ◽  
Cement Ratio ◽  
Water Cement Ratio ◽  
Coarse Aggregates ◽  
Flow Test ◽  
Pozzolanic Properties

Abstract The compressive strength properties of concrete are substantial factors in the design and construction of concrete structures. Compressive strength directly affects the degree to which the concrete can be able to carry a load over time. These changes are complemented by deflections, cracks etc., in the structural elements of concrete. This research investigated the effect of groundnut leaf/stem ash (GLSA) on the compressive strength of concrete at 0%, 5 %, 10 % and 15 % replacements of cement. The effect of the water-cement ratio on properties such as the compressive strength, slump, flow and workability properties of groundnut leaf/stem ash (GLSA) mixes with OPC were evaluated to determine whether they are acceptable for use in concrete structural elements. A normal concrete mix with cement at 100 % (i.e., GLSA at 0%) with concrete grade C25 that can attain an average strength of 25 N/mm2 at 28 days was used as a control at design water-cement ratios of 0.65 and grading of (0.5-32) mm from fine to coarse aggregates was tested for: (1) compressive strength, and the (2) slump and flow Test. The results and observations showed that the concrete mixes from GLSA at 5 – 15 % ratios exhibit: pozzolanic properties and GLSA could be used as a partial replacement for cement at these percentage mix ratios compared with the control concrete; an increase in the water-cement ratio showed a significant decrease in the compressive strength and an increase in workability. Therefore, it is important that all concrete mixes exude an acceptably designed water-cement ratio for compressive strength characteristics for use in structures, water-cement ratio is a significant factor.

Efficiency of Limestone Powder in SCC

2012 ◽  
Vol 1488 ◽  
Author(s):  
K. Ganesh Babu ◽  
B. Chandra Sekhar
Keyword(s):  
Compressive Strength ◽  
Mechanical Strength ◽  
Mineral Admixture ◽  
Strength Characteristics ◽  
Limestone Powder ◽  
Cement Ratio ◽  
Water Cement Ratio ◽  
Topical Interest

ABSTRACTSelf-compacting concretes have been of topical interest due to the ease of adoption and the significant savings in compaction efforts particularly at the congested reinforcement locations, in spite of the leak-proof forms required. However, many of the aspects regarding their production with different powder or pozzolanic additions and their corresponding mechanical strength characteristics are not yet fully understood. This paper deals exclusively with the compressive strength characteristics of these concretes incorporating limestone powder as a mineral admixture through the water cement ratio to strength results of concretes reported in literature. The basic idea is to get an idea of the SCCs at the lowest and the highest possible amounts of the limestone powder in it.

Preparation and Study on the Performance of Polymer-Modified Cement-Based Composite Insulation Materials

2014 ◽  
Vol 541-542 ◽  
pp. 57-60 ◽  
Author(s):  
Xiao Long Li ◽  
Guo Zhong Li ◽  
Ling Wang ◽  
Yu Zhong Liu
Keyword(s):  
Composite Material ◽  
Water Absorption ◽  
Optimal Dosage ◽  
Action Mechanism ◽  
Cement Ratio ◽  
Water Cement Ratio ◽  
Foam Stabilizer ◽  
Internal Morphology ◽  
Influence Of Water ◽  
Scanning Electron

In the experiment, the influence of water-cement ratio on the strength of composite material was studied, and the optimal water-cement ratio was 0.45. The influence of different dosages of foam stabilizer on the mechanical properties of composite material was studied, and the optimal dosage of foam stabilizer was 3%. And the influence of different dosages of polymer on the strength and water absorption of composite material was studied, and the optimal dosage of polymer was 1.5%. In this ratio, the compressive strength is 0.53 MPa, flexural strength is 0.39 MPa, 2h water absorption is 41.1%, 24h water absorption is 43.1% and thermal conductivity is 0.048 W/(m·K). Meanwhile, scanning electron microscopy is used to observe the internal morphology of the samples, and the related action mechanism is explored.

Strength Indicators Of Cement Systems With Additives Of Surface - Active Substances

2021 ◽  
Vol 03 (05) ◽  
pp. 203-209
Author(s):  
Teshaboeva Nodira Djuraevna ◽  
Keyword(s):  
Mineralogical Composition ◽  
Strength Characteristics ◽  
Cement Ratio ◽  
Water Cement Ratio ◽  
Surface Active ◽  
Active Substances ◽  
Control Samples

In the article, the study was to establish the effect of surfactant additives on the strength characteristics of cement systems. The determinations were carried out on cements of various mineralogical composition, freshly ground and stale, on cement-sand mortars and concretes. For control samples and with additives, the same plasticity was chosen, and the water-cement ratio than for various additives fluctuated within certain limits.

scholarly journals Use of Nondestructive Testing of Ultrasound and Artificial Neural Networks to Estimate Compressive Strength of Concrete

Buildings ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 44
Author(s):  
Fernando A. N. Silva ◽  
João M. P. Q. Delgado ◽  
Rosely S. Cavalcanti ◽  
António C. Azevedo ◽  
Ana S. Guimarães ◽  
...  
Keyword(s):  
Neural Networks ◽  
Compressive Strength ◽  
Artificial Neural Networks ◽  
Cross Sections ◽  
Influential Factors ◽  
Average Error ◽  
Ann Model ◽  
Cement Ratio ◽  
Water Cement Ratio ◽  
Artificial Neural

The work presents the results of an experimental campaign carried out on concrete elements in order to investigate the potential of using artificial neural networks (ANNs) to estimate the compressive strength based on relevant parameters, such as the water–cement ratio, aggregate–cement ratio, age of testing, and percentage cement/metakaolin ratios (5% and 10%). We prepared 162 cylindrical concrete specimens with dimensions of 10 cm in diameter and 20 cm in height and 27 prismatic specimens with cross sections measuring 25 and 50 cm in length, with 9 different concrete mixture proportions. A longitudinal transducer with a frequency of 54 kHz was used to measure the ultrasonic velocities. An ANN model was developed, different ANN configurations were tested and compared to identify the best ANN model. Using this model, it was possible to assess the contribution of each input variable to the compressive strength of the tested concretes. The results indicate an excellent performance of the ANN model developed to predict compressive strength from the input parameters studied, with an average error less than 5%. Together, the water–cement ratio and the percentage of metakaolin were shown to be the most influential factors for the compressive strength value predicted by the developed ANN model.

Study on Preparation of Solid Concrete Brick with Recycled Aggregate

2013 ◽  
Vol 648 ◽  
pp. 108-111
Author(s):  
Qi Jin Li ◽  
Guo Zhong Li
Keyword(s):  
Compressive Strength ◽  
Mass Fraction ◽  
Recycled Aggregate ◽  
Preparation Process ◽  
Mass Ratio ◽  
Construction Waste ◽  
Cement Ratio ◽  
Water Cement Ratio ◽  
Optimal Value

The construction waste was processed into recycled aggregate to produce solid construction waste brick with grade of MU20. The preparation process of recycled aggregate and the optimal value of mass ratio of water to cement (water cement ratio) and mass ratio of recycled aggregate to cement was studied. The results shows that when the water cement ratio is 0.86 and the mass ratio of recycled aggregate to cement is 5.5 and the dosage of activator is 0.25% (mass fraction with recycled aggregate), the compressive strength of sample is 22.5MPa and can be satisfied with the requirement of MU20 solid concrete brick.

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