scholarly journals Study of the influence of modern superplastificators on the properties of road cement concrete

2021 ◽  
Vol 2 (92) ◽  
pp. 74
Author(s):  
Serhii Tolmachov ◽  
Olena Belichenko ◽  
Oleksandr Moskalenkо ◽  
Yurii Pokusa
Keyword(s):  
Water Demand ◽  
Concrete Strength ◽  
Cement Concrete ◽  
Chemical Additives ◽  
Actual Problem ◽  
The Road ◽  
Concrete Mixtures ◽  
Modern Chemical ◽  
Cast Concrete ◽  
Effective Use

Abstract. In the technology of road concrete, the use of plasticizing additives is mandatory. In the last century, the most widely used plasticizers are lignosulfonates. These additives reduce the water demand of concrete mixtures by 10...15 % and increase the strength of concrete by 20...25 %. However, the presence of sugars in their composition leads to a strong slowdown of the hardening processes and can lead to a decrease the strength of concrete at the age of 28 days. In this century, modern superplasticizers based on polycarboxylates began to be widely used in industrial and civil construction. They were mainly used for the manufacture of cast concrete mixtures. On the other hand, their use in moderately mobile concrete mixes allows reducing water demand by 35...40 % and increasing strength by 60...100 % compared to concretes without additives. However, in such mixtures the use of polycarboxylates leads to a quick setting of the ce-ment and an accelerated set of concrete strength. This does not meet the requirements of the road concrete standards. The goal of the work is to study the influence of modern chemical additives of various nature on the basic properties of road cement con-crete. The article is devoted to the actual problem of the effective use of polycarboxylate superplasticizers

scholarly journals IMPROVING THE DURABILITY OF CEMENT CONCRETE TO COVER ROADS

2020 ◽  
Vol 1 (46) ◽  
pp. 324-332
Author(s):  
Stozhka V ◽  
◽  
Borkowski P ◽  
Keyword(s):  
Road Construction ◽  
Small Scale ◽  
Water Repellent ◽  
Cement Concrete ◽  
Chemical Additives ◽  
Scientific Publications ◽  
The Road ◽  
Security Issues ◽  
Cement Concrete Pavement ◽  
Object Of Study

The article is devoted to the problem of improving the durability of cement concrete to cover the road through the use of additives. The purpose of the work-improving the durability of cement concrete to cover roads through the use of hydrophobic additives. Object of study-cement-concrete to cover roads. Method of research: statistical analysis of scientific publications, technical and normative literature. In Ukraine, there are almost no necessary types and brands of road cement, so the research and application of existing binders with effective additives is an urgent problem, the solution of which will expand the nomenclature of cement binders for road Construction, improve the durability and resistance of cement concrete covering roads, bridges and airfields, as well as to solve security issues. For this, it is possible to use chemical additives that kolatating pores, give the surface of concrete water-repellent properties, involve in the concrete mixture of air. Based on the modern representations of the physical- xiemia of superficial processes, it can be concluded that the introduction to the concrete mix of small-scale kremnijorganicnih substances together with the water of the closing, will allow to significantly improve the durability and strength against At the same time for the concrete of aggressive factors and load. The influence of hydrophobic additives on physical, mechanical properties of cement concrete to cover roads is investigated. Based on the experimental results, it is determined that the application of 0.1­0.15% hydrophobic additives 136-157 M has a significant increase in the durability of cement concrete for the seal of roads. KEYWORDS: CEMENT CONCRETE PAVEMENT, HYDROPHOBIC ADDITIVES, FROST RESISTANCE, WATER RESISTANCE, STRENGTH, DURABILITY

scholarly journals The use of cement concrete pavements for roads, depending on climatic conditions

2019 ◽  
Vol 13 (3) ◽  
pp. 235-240
Author(s):  
Iryna Solonenko
Keyword(s):  
European Union ◽  
Statistical Models ◽  
Road Network ◽  
The European Union ◽  
Rational Selection ◽  
Cement Concrete ◽  
The Road ◽  
Road Pavement ◽  
Operational Characteristics ◽  
Selection Of

The development of road network infrastructure is an important component of the economic development of the European Union. Updating of the road network contributes to the integration of the economies of countries into a coherent whole. The road network provides the free movement of citizens, the movement of goods and the effective implementation of various services. The increase in the length of the road network leads to an increase in the financial and material costs necessary to ensure its maintenance and repair. One of the ways to reduce costs is by strengthening the physic-mechanical and operational characteristics of the pavement due to the widespread use of cement concrete. The quality of the pavement of cement concrete depends largely on the rational selection of its composition. This allows a significant increase in the durability of road pavement. The purpose of the research was: the development of recommendations for the rational selection of the composition of the road pavement material of cement concrete, aimed at upgrading longevity, and taking into account its frost resistance grade. According to the goal, the following tasks were developed: the analyses of the climatic zones in which the road network of the European Union is located; the development of a research plan, a selection of the response function and influence factors; the study of physico-mechanical and operational characteristics of the researched material of road pavement; on the basis of the obtained data, the calculation of the complex of experimental-statistical models, which describe the physico-mechanical and operational characteristics of the road pavement material; on the basis of experimental statistical models, a method was proposed for selecting the rational compositions of the cement concrete pavement road material depending on the conditions of its application. The results presented in the article can be used in engineering and scientific practice for the selection of road pavement from cement concrete for highways.

scholarly journals Experimental Study on Recycling of Bituminous Aggregate in Cement Concrete

2021 ◽  
Vol 9 (VI) ◽  
pp. 5392-5398
Author(s):  
Manoj Kumar Mishra
Keyword(s):  
Experimental Study ◽  
Road Construction ◽  
Construction Cost ◽  
Recycled Aggregate ◽  
Recycled Aggregates ◽  
Cement Concrete ◽  
Cost Component ◽  
The Road ◽  
Total Construction Cost ◽  
Recycled Material

Recycling of bituminous aggregates in cement concrete has been selected for the present study to determine suitability of recycled material in road construction. This will help in achieving economy in road construction as well as saving on environment degradation in term of reduced mining and less pollution. Construction and maintenance of roads and highways involve millions of tonnes of aggregate. Considering the scarcity of fresh aggregate, replacement of part of the fresh aggregate with recycled aggregate is considered in the present study. Construction of the road is quite cost intensive. Material alone cost more than 60% of the total construction cost, out of which aggregate cost component, is approximately 30%. We can use recycled aggregate in place of fresh aggregate in construction of road and provide economy to the project. For making best use of recycled aggregates, it is essential to study the suitability of the same in various pavement components. In the present study recycled aggregate are used in Granular Sub Base (GSB) and Wet Mix Macadam (WMM).

scholarly journals Effects of microbial agents to the properties of fly ash-based paste

2018 ◽  
Vol 195 ◽  
pp. 01012
Author(s):  
Kiki Dwi Wulandari ◽  
Januarti Jaya Ekaputri ◽  
Triwulan ◽  
Chikako Fujiyama ◽  
Davin H. E. Setiamarga
Keyword(s):  
Fly Ash ◽  
Portland Cement ◽  
Cement Paste ◽  
Construction Material ◽  
Concrete Strength ◽  
Self Healing ◽  
Concrete Mixtures ◽  
Microbial Agents ◽  
Portland Cement Paste ◽  
Geopolymer Paste

Specific microbial agents such as bacteria are often used in concrete to improve its performance. Some microbes act as self-healing agents to close cracks in concrete, and to increase concrete strength. This paper presents a study to observe the effects of microbe addition to two types of concrete mixtures the fly ash-based, as geopolymer paste, and portland cement paste containing fly ash. Furthermore, the investigation was conducted to compare the properties of each paste, such as its compressive strengths, specific gravities, porosity, microstructures, and XRay diffracting properties. The results indicate that microbial activities positively affected the properties of both, portland cement paste and geopolymer paste. The result reported here strongly suggests that fly ash can be used to produce a high quality, but environmental friendly construction material when it’s mixed together with useful microbes.

Ice Formation as an Indicator of Frost-Resistance on the Concrete Containing Slag Cement in Conditions of Freezing and Thawing

2016 ◽  
Vol 865 ◽  
pp. 145-150
Author(s):  
Oleksandr Moskalenko ◽  
Rayisa Runova
Keyword(s):  
Frost Resistance ◽  
Ice Formation ◽  
Cement Concrete ◽  
Chemical Additives ◽  
Freezing And Thawing ◽  
Slag Cement ◽  
Mineral Supplement

The connection with the icing on the frost resistance of concrete containing slag cement and chemical additives «MC Bauchemie» under freezing and thawing.It is shown that freeze concrete samples at (-) 10°C increase in the amount of slag from 30 to 70 wt.% Of binder in the composition leads to an increase in the index of ice formation in the concrete of 1.7 ... 1.9 times compared with the concrete obtained at a slag containing slag cement with a content of 10 wt.%. Frost resistance of concrete is reduce from F450 to F400.When freezing of concrete samples at (-) 20°C increase in the amount of slag from 30 to 50 wt. % Binder in the composition leads to an increase in the index of ice formation in the concrete of 1.7 times compared with the concrete obtained on slag cement containing slag with a content of 10 wt.%. Frost resistance of concrete is reduce from F400 to F350.The concrete on the slag containing cement with slag 70 wt. % is observed a slight decrease in ice formation. However, its value is 1.4 times higher than ice formation in concretes containing slag in an amount of 10 wt. %. Mark on frost resistance remains at F350.The smallest ice formation, regardless of the content of the slag into the slag containing cement, concrete characterized in that use complex organo-mineral supplement SX (5%) + SP (0.6%) in the amount of 5.6%. According to the degree of influence of additives used to reduce ice formation in the slag in concretes, containing cements can be ranker number: SX (5%) + SP (0.6%) > NC (5%) + SP (0.6%) > SP (0.6%).

scholarly journals Estimation of In-situ concrete strength using drilling resistance

2019 ◽  
Vol 289 ◽  
pp. 06001
Author(s):  
Serkan Karatosun ◽  
Muhammet Asan ◽  
Oguz Gunes
Keyword(s):  
Compressive Strength ◽  
Concrete Strength ◽  
Condition Assessment ◽  
Assessment Practice ◽  
Destructive Testing ◽  
Seismic Safety ◽  
Concrete Mixtures ◽  
Priority Task ◽  
Compressive Strength Of Concrete ◽  
Drilling Resistance

Rapid and reliable condition assessment of reinforced concrete structures in high seismicity regions is a priority task in estimating their seismic safety. Non-destructive testing (NDT) methods may contribute to the condition assessment practice by providing fast and reliable strength estimation while causing minimal or no damage to the structure. Drilling resistance is an NDT method that has been used for mechanical characterization of natural stone and wood by measuring the force response for constant penetration rate and rotational speed. This paper focuses on the relationship between drilling resistance and compressive strength of concrete, including when it is combined with other NDT methods. Concrete cube samples produced using 6 different concrete mixtures were tested. Correlation equations were then obtained using statistical analysis. The results reveal that it may be possible to reliably estimate the compressive strength of concrete using drilling resistance method.

Cullet-Filled Concrete

2020 ◽  
Vol 992 ◽  
pp. 73-78
Author(s):  
V.N. Shishkanova ◽  
M.V. Ivanko ◽  
Andrey Yu. Kozlov
Keyword(s):  
Silica Fume ◽  
Large Particle ◽  
Concrete Strength ◽  
Highly Dispersed Silica ◽  
Concrete Mixtures ◽  
Highly Dispersed ◽  
Polymer Component ◽  
Rock Microstructure ◽  
Very High ◽  
Cullet Content

The paper considers how cullet of different particle-size distribution affects the concrete strength. Experiments have proven that large-particle cullet (1.25 cm or larger) could be used as an aggregate; the concrete strength will be on par with those of ordinary natural/crushed sand concrete. The paper proves the feasibility of injecting highly dispersed silica fume in combination with effective polycarboxylate-based superplasticizers in cullet-based concrete mixtures. Highly dispersed silica fume will positively affect the strength characteristics of concrete, as silica fume in cement rock reacts with Са (ОН)2, which is released upon the hydration of the clinker minerals С3S and С2S; the reaction produces very strong compounds. Concretes containing up to 30% silica fume in combination with a superplasticizer will feature very high early strength. Use of strong aggregates with a 30% cullet content can produce strong concretes; after steamed, a concrete containing silica fume and polycarboxylate-based superplasticizer will reach 90% of the graded strength. Cement-rock microstructure studies show that the polymer component of the STACHEMENT 2280 superplasticizer will gradually transcend from the glass grains to the cement rock. The interface between the polymer-coated glass grains and the cement rock is blurred and barely present. This strengthens the glass-rock adhesion and improves the concrete strength. This is why cullet is recommended for use in the production of curb stones.

scholarly journals Checking the conformity of the grain-size composition of road cement concrete mixtures

2019 ◽  
Vol 110 ◽  
pp. 01051
Author(s):  
Artur Onyshchenko ◽  
Sergii Aksonov ◽  
Vitalii Stozhka ◽  
Mykola Garkusha ◽  
Alexandr Matusevich
Keyword(s):  
Grain Size ◽  
Quality Control ◽  
Experimental Research ◽  
Size Composition ◽  
Cement Concrete ◽  
Grain Composition ◽  
Concrete Mixtures ◽  
Number Of Factors ◽  
Operational Quality

The article is devoted to operational quality control of grainsize composition of cement-concrete road mixtures for use on highways of Ukraine. The results of the experimental research are presented, which testify to the non-conformity of the planned grain composition to the actual production composition, as well as the influence on it of a number of factors that significantly affect the quality of the mixture and the durability of cement concrete.

scholarly journals Recommendations for determining the thickness of the road pavement of technological roads built from coal-bearing rocks

2019 ◽  
Vol 134 ◽  
pp. 01013
Author(s):  
Victor A. Shalamanov ◽  
Sergey N. Shabaev ◽  
Faruz Alama
Keyword(s):  
Asphalt Concrete ◽  
Open Pit ◽  
Open Pit Mining ◽  
Coal Production ◽  
Mining Method ◽  
Cement Concrete ◽  
Mining Company ◽  
The Road ◽  
Road Pavement ◽  
The Cost

With open-pit mining method in Kuzbass is widely used automobile transport, transportation costs up to 70% of the cost of coal production. It is not economically feasible to use asphalt concrete and cement concrete as a material of temporary technological roads, and the use of crushed coal-bearing rocks will make it possible to increase the efficiency of coal mining by open method. Currently, the question of the application of the coal-bearing rocks for building temporary technological roads is poorly studied. The paper proposes a method of determining the thickness of road pavements of technological roads, which can be applied directly by the mining company, their analysis has been carried out, the dependence from the strength factor and the category of blockiness of foundation rocks has been determined.

Sign in / Sign up

Export Citation Format

Share Document