scholarly journals Special Concrete with Polymers

2016 ◽  
Vol 14 (11) ◽  
pp. 7-10
Author(s):  
Nicolae Angelescu ◽  
Ioana Ion ◽  
Darius Stanciu ◽  
José Barroso Aguiar ◽  
Elena Valentina Stoian ◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Portland Cement ◽  
Epoxy Resin ◽  
Raw Materials ◽  
Polymeric Materials ◽  
Polymer Concrete ◽  
Fine Aggregate ◽  
Concrete Mixtures ◽  
Experimental Works ◽  
Materials Used

Abstract The development of polymeric materials offers new perspectives of science and technology due to their outstanding properties. These properties are obtained either due to the effect of dispersion polymers and their polymerization either due to their intervention in structure formation. They were prepared epoxy resin polymer concrete, Portland cement, coarse and fine aggregate and to evaluate the influence of resin dosage on microstructures and density of such structures reinforced concrete mixtures. The paper detailing the raw materials used in experimental works and structural properties of concrete studied.

scholarly journals AN EFFECTIVE WAY TO RECYCLE 3D PRINTING CONCRETE SCRAP

2021 ◽  
Vol 4 (2) ◽  
pp. 12-18
Author(s):  
D.A. Tolypin ◽  
N. Tolypina
Keyword(s):  
Compressive Strength ◽  
3D Printing ◽  
Portland Cement ◽  
Quartz Sand ◽  
Raw Materials ◽  
Electricity Consumption ◽  
Cement Matrix ◽  
Fine Aggregate ◽  
Fine Grained ◽  
Control Samples

the article proposes a rational method for processing 3D printing concrete scrap using vibration equipment, which allows obtaining a multicomponent building material with minimal electricity consumption. As a crite-rion for the degree of grinding of concrete scrap, it is proposed to use the specific surface area of the finely dispersed part of concrete scrap, which should correspond to 400-500 m2/kg. The possibility of reusing the resulting product instead of the traditional fine aggregate of quartz sand is shown. It was found that the con-crete scrap without the addition of Portland cement hardens, reaching up to 48% of the compressive strength of the control samples by 28 days. When 10% of the binder CEM I 42.5 N was added to the concrete scrap processing product, the compressive strength of fine-grained concrete increased by 106.6%, and 20% of Portland cement - by 112.2 %, compared to the strength of control samples of a similar composition on tra-ditional quartz sand after 28 days of hardening. It is noted that this is primarily due to the weak contact zone of quartz sand and the cement matrix of concrete. The use of the product of processing concrete scrap al-lows obtaining building composites based on it with the complete exclusion of natural raw materials

Development of Low-Activation Design Method for Reduction of Radioactive Waste Below Clearance Level

2008 ◽  
Author(s):  
Ken-Ichi Kimura ◽  
Akira Hasegawa ◽  
Katsumi Hayashi ◽  
Mikio Uematsu ◽  
Tomohiro Ogata ◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Portland Cement ◽  
Power Plants ◽  
Raw Materials ◽  
Development Project ◽  
Radiation Shielding ◽  
Benchmark Calculation ◽  
Steel Bars ◽  
Clearance Level ◽  
Selection Of

Design methodology for reinforced concrete of nuclear power plants to reduce radioactive wastes in decommission phase has been developed. To realize this purpose, (1) development of raw materials database of cements, aggregates and steel bars on concentration of radioactive target elements, (2) trial production of low activation cements and steel bars based on the material database developed in (1), and (3) development of tools for estimation and prediction of the amount of radioactive elements in reactor shielding walls have been carried out. Radioactive analysis showed that Co and Eu were the major target elements which decide the radioactivity level of reinforced concrete from wide survey of raw materials for concrete (typically aggregates and cements). Material database for the contents of Co and Eu was developed based on the chemical analysis and radioactivation analysis. Upon the above survey and execution expreiment of concrete, six types of low-activation concrete are proposed for various radioactive portion in the plant. These concrete have a 1/10 – 1/300 rasioactivity compare to the ordinary concrete, which are assumed the concrete with Andesite aggregate and ordinary Portland cement. Baed on the above data base, it was clarified that the low activation cement would be successfully manufactured by adequate selection of raw materials. The prospect to produce the low-heat portland cement which would have a 1/3 radioactivity in comparison with conventioanl cements obtained by means of selection of limestone and natural gypsum. An attempte was carried out to produece low activation heavy-mortar which would have radioactivity below the clearance level when using at the radiation shielding wall of BWR. Characterization and optimization of consturction conditions with new additives have also been carried out. These two new raw materials for low-activation concrete are conducted in pre-manufacture size, and over the laboratry level. Boron added low-activation concrete are also carried out as extreamly high performance low-activation concrete. It was claryfied that the accurcy of calculation results of the radioactivity evaluation was very high compared to available benchmark calculation for the JPDR and commercial light water reactor. The specification of the mapping system for judging the activation classification was also developed by using the general-purpose radio activation calculation tool. This work is supported by a grant-in-aid of Innovative and Viable Nuclear Technology (IVNET) development project of Ministry of Economy, Trade and Industry, Japan.

scholarly journals Evaluation of modulus of elasticity for eco-friendly concrete made with seawater and marine sand

2021 ◽  
Vol 15 (4) ◽  
pp. 148-156
Author(s):  
Tu T. Nguyen ◽  
Pham Thanh Tung ◽  
Kobir Hossain
Keyword(s):  
Portland Cement ◽  
Experimental Work ◽  
Modulus Of Elasticity ◽  
Sodium Sulfate ◽  
Empirical Equation ◽  
Fine Aggregate ◽  
Geopolymer Concrete ◽  
Concrete Mixtures ◽  
Marine Sand ◽  
Over Time

The ultimate aim of this study is to use experimental work for evaluating the modulus of elasticity (MOE) of Geopolymer concrete (GPC) using marine sand as fine aggregate and seawater for the mix. Four different groups of concrete mixtures, namely CP1a, CP1b, CP2a, CP2b were identified. While the CP1a mix was prepared using GPC with marine sand and seawater, the CP1b was made by adding sodium sulfate (Na2SO4) into the CP1a mix. The same procedure was applied for CP2a and CP2b mixtures; however, instead of using GPC, Portland Cement was used as the binder for the CP2 group (OPC). A total of 12 test samples were cast and tested to determine the development of MOE of GPC and OPC over time. The MOE of concrete was measured at 3, 7, 28, 60, and 120 days. Experimental results were then compared to the MOE obtained using the empirical equation from ACI 318 - 2008. It was found that the experimental MOE of both OPC and GPC specimens was higher than the estimated MOE values from ACI standards. The added sodium sulfate yielded a significant effect on the MOE of OPC but produced a minimal influence on the MOE of GPC.

scholarly journals KARAKTERISTIK MEKANIS BETON YANG MENGGUNAKAN IRON SLAG SEBAGAI AGREGAT HALUS

2020 ◽  
Vol 20 (3) ◽  
pp. 223-230
Author(s):  
Hijriah ◽  
Nur Hadijah Yunianti
Keyword(s):  
Test Object ◽  
Environmentally Friendly ◽  
Fine Aggregate ◽  
Iron Slag ◽  
Concrete Mixtures ◽  
Fine Aggregates ◽  
Materials Used ◽  
Slag Waste ◽  
Test Objects ◽  
Research Analysis

The demand for environmentally friendly concrete mixtures is currently increasing due to an increase in global temperatures. Therefore, innovation is needed in the world of Civil Engineering to produce structures that can reduce global warming. One alternative that can be taken is by utilizing materials from environmentally friendly products such as Iron Slag. This study aims to determine the characteristics of the aggregate and to analyze the strength of the concrete mixture using Iron Slag as a substitute for fine aggregate. This research is an experimental study which was conducted in the Laboratory of Concrete and Structural Materials, Bosowa University. Variations in the test object were the levels of addition of Iron Slag with levels of 0%, 25% and 50%. The test object will be observed at the age of 28 days, where the number of test objects is 29 pieces. The tests carried out include testing the characteristics of the materials used, both coarse and fine aggregates, as well as testing the compressive strength of the concrete. Based on the results of the research analysis, it was concluded that Iron Slag waste met the criteria as fine aggregate for concrete mixtures.

scholarly journals Experimental Investigations on the Properties of Epoxy-Resin-Bonded Cement Concrete Containing Sea Sand for Use in Unreinforced Concrete Applications

Materials ◽  
2019 ◽  
Vol 12 (4) ◽  
pp. 645 ◽  
Author(s):  
Sakthieswaran Natarajan ◽  
Nagendran Neelakanda Pillai ◽  
Sophia Murugan
Keyword(s):  
Epoxy Resin ◽  
Experimental Studies ◽  
Sem Analysis ◽  
Polymer Concrete ◽  
Experimental Investigations ◽  
Clear Understanding ◽  
Fine Aggregate ◽  
Practical Applications ◽  
Durability Properties ◽  
Sea Sand

This paper deals with the experimental studies conducted on the effects of using sea sand on the properties of polymer concrete modified using epoxy resin. The physical properties including workability, mechanical properties, and durability properties were evaluated as a function of sea-sand substitution. The results obtained behave as strong evidence for the feasibility of using sea sand as fine aggregate to solve the problem associated with the exhaustion of natural aggregates when used in combination with epoxy polymer. A clear understanding of the behavior of polymer concrete with sea sand as aggregate was obtained through some preliminary investigations. The test results showed a significant improvement in the compressive and flexural strength due to the sea-sand substitution in polymer concrete. Resistance to the water intrusion was also improved for the concrete mixes due to the inclusion of epoxy resin. The quality and the integrity of the concrete were also improved,as evident from the SEM analysis and infrared (IR) spectroscopy, and the results function as solid basis for the use of sea-sand polymer-modified concrete for practical applications. Results also show that 15% replacement of fine aggregate by sea sand in air-cured polymer concrete exhibited enhanced strength and durability properties; thus, the produced concrete can be an effective material for unreinforced concrete applications.

Fine-Grained Fibre Concrete of Run-Of-Crusher Stone Using Volcanic Ash

2021 ◽  
Vol 1043 ◽  
pp. 61-65
Author(s):  
Tolya Khezhev ◽  
Aslan Kardanov ◽  
Eldar Bolotokov ◽  
Azamat Dottuyev ◽  
Ibrahim Mashfezh
Keyword(s):  
Reinforced Concrete ◽  
Raw Materials ◽  
Concrete Strength ◽  
Basalt Fiber ◽  
Strength Properties ◽  
Fiber Reinforced Concrete ◽  
Fiber Reinforced ◽  
Fine Grained ◽  
Concrete Mixtures ◽  
Polyfunctional Additive

The results of the studies on the creation of self-compacting fine-grained fiber-reinforced concrete based on run-of-crusher stone with the use of a polyfunctional additive D-5 are presented. Compositions of self-compacting fine-grained fiber-reinforced concrete with the use of basalt fiber have been developed, which significantly reduce cement consumption and improve the characteristics of fine-grained concrete mixture and concrete. Using a polyfunctional additive D-5in mixtures makes it possible to increase the strength properties of fine-grained fiber-reinforced concrete while improving the concrete mixtures’ rheological characteristics. Replacement of cement up to 10% of the mass by ash fraction d<0.14 min fine-grained concrete mixtures does not cause a noticeable decrease in the concrete strength properties. The developed self-compacting fine-grained fiber-reinforced concretes have increased strength properties and have a low-cost price due to the use of local raw materials and run-of-crusher stone.

Determination of zinc in cassava based polymeric materials

2021 ◽  
pp. 089270572110138
Author(s):  
Rada-Mendoza Maite ◽  
Chito-Trujillo Diana ◽  
Hoyos-Saavedra Olga Lucía ◽  
Arciniegas-Herrera Jose Luis ◽  
Molano-Tobar Nancy Janneth
Keyword(s):  
Food Packaging ◽  
Raw Materials ◽  
Polymeric Materials ◽  
Statistical Parameters ◽  
Intermediate Precision ◽  
Flexible Films ◽  
Flame Atomic Absorption ◽  
Zinc Concentrations ◽  
Materials Used

The current trends in biodegradable food packaging include the use of materials such as biopolymers which should be free of toxic metals to ensure their quality and use in multiple applications. However, these samples can contain zinc given its presence in the materials used to make them. In this study, a method to determine the concentration of zinc (Zn) in thermoformed and biodegradable flexible films samples based on Cassava and in their raw materials (flour, starch and fique) using flame-atomic absorption spectroscopy is described. Prior, an acid digestion with nitric acid under reflux was required. The method was standardized by means of the evaluation of statistical parameters. The method was sufficiently lineal ( R2 = 0.999) in a working range from 0.1 to 1.0 mg Zn/L with detection and quantification limits of 0.03 and 0.82 mg/L, respectively. The method was found to be precise and accurate, and could therefore be used to measure Zn content at levels well below safe limits.The precision of the method was evaluated using intermediate precision and repeatability which showed coefficients of variation less than 6.7% and 4.7%, respectively. The percentages of recovery ranged from 96.5% to 98.2%. The method was successfully applied for the determination of Zn in the studied biopolymers samples and the results obtained support the method’s suitability for determining the presence of the metal. Zinc concentrations in thermoformed, flexible films and flour were below 2.36, 2.14 and 2.01 mg/L, respectively, indicating that these polymers could be used for food containers.

scholarly journals Studi Kelayakan Penggunaan Cangkang Kemiri Sebagai Pengganti Sebagian Agregat Kasar Terhadap Mutu Beton

2020 ◽  
pp. 41-46
Author(s):  
H. Haris
Keyword(s):  
Compressive Strength ◽  
Natural Resources ◽  
Coarse Aggregate ◽  
Building Construction ◽  
Fine Aggregate ◽  
Construction Sector ◽  
Concrete Compressive Strength ◽  
Concrete Mixtures ◽  
Materials Used ◽  
Renewable Natural Resource

In the current era of globalization, the development of concrete in the construction sector is very rapid, be it housing, offices, bridges, roads, dams, ports, and others. That is inseparable from the use of concrete as a part of building construction. The use of coarse aggregate for concrete mixes, namely natural stone, is a non-renewable natural resource. Therefore an alternative is needed as a substitute. One of the natural resources that can be renewed is hazelnut skin. Candlenut is a traditional plant that has various benefits, one of which is a candlenut shell. In this study, the materials used for standard concrete mixtures consist of water, cement, fine aggregate, and coarse aggregate. The water used for mixing the concrete is taken from the PDAM channel. The results showed that the effect of candlenut shells used as a substitute for some coarse aggregate decreased compressive strength results from the results of standard concrete compressive strength. The results obtained by the value of standard concrete compressive strength at 28 days of concrete were 27.19Mpa for concrete using Candlenut shells of 20% produce a compressive strength value of 17.33 Mpa at 28 days of concrete. 35% produce a concrete compressive strength value of 16.04 Mpa, while 50% produce a concrete compressive strength value of 15.17 Mpa. Thus the research shows that more and more candlenut shells are being used as a substitute for coarse aggregate in the concrete mixture.

scholarly journals Effect of Silica Fume and Fly Ash Admixtures on the Corrosion Behavior of AISI 304 Embedded in Concrete Exposed in 3.5% NaCl Solution

Materials ◽  
2019 ◽  
Vol 12 (23) ◽  
pp. 4007 ◽  
Author(s):  
Miguel Angel Baltazar-Zamora ◽  
David M. Bastidas ◽  
Griselda Santiago-Hurtado ◽  
José Manuel Mendoza-Rangel ◽  
Citlalli Gaona-Tiburcio ◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Fly Ash ◽  
Portland Cement ◽  
Silica Fume ◽  
Corrosion Behavior ◽  
Supplementary Cementitious Materials ◽  
304 Stainless Steel ◽  
Corrosion Monitoring ◽  
Aisi 304 ◽  
Concrete Mixtures

The use of supplementary cementitious materials such as fly ash, slag, and silica fume improve reinforced concrete corrosion performance, while decreasing cost and reducing environmental impact compared to ordinary Portland cement. In this study, the corrosion behavior of AISI 1018 carbon steel (CS) and AISI 304 stainless steel (SS) reinforcements was studied for 365 days. Three different concrete mixtures were tested: 100% CPC (composite Portland cement), 80% CPC and 20% silica fume (SF), and 80% CPC and 20% fly ash (FA). The concrete mixtures were designed according to the ACI 211.1 standard. The reinforced concrete specimens were immersed in a 3.5 wt.% NaCl test solution to simulate a marine environment. Corrosion monitoring was evaluated using the corrosion potential (Ecorr) according to ASTM C876 and the linear polarization resistance (LPR) according to ASTM G59. The results show that AISI 304 SS reinforcements yielded the best corrosion behavior, with Ecorr values mainly pertaining to the region of 10% probability of corrosion, and corrosion current density (icorr) values indicating passivity after 105 days of experimentation and low probability of corrosion for the remainder of the test period.

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