The Influence of the Structure on the Destruction Mechanism of Polymer-Cement Plaster Coating

2020 ◽  
Vol 864 ◽  
pp. 93-100
Author(s):  
Valentyn Paruta ◽  
Olga Gnyp ◽  
Leonid Lavrenyuk ◽  
Iryna Grynyova

The article considers the influence of the structure of polymer-cement plaster coating on the nature of its destruction during the operation of the wall structure. It was shown that the use of purposefully selected components of the mixture (RPP, polymer fiber, cellulose ethers, fine aggregate with a low modulus of elasticity, etc.) made it possible to increase the uniformity of its structure and contact area with masonry, reduce the number of cracks during hardening, and slow down their development during operation, increase the durability of it and the wall structure. The durability of the wall structure largely depends on the number of defects in the plaster coating and the contact area between it and the masonry.

Author(s):  
Valentyn Paruta ◽  
Olha Gnyp ◽  
Leonid Lavreniuk ◽  
Bachinsky Vyacheslav Bachinsky Vyacheslav ◽  
Iryna Grynyova

High-rise construction volume increase and new wall materials use require changing the approach to the design of plastermortar compositions. The analysis has showed that it is possible to reduce the number of cracks in the plaster coating by increasingthe water holding capacity of the mortar mixture. To optimize the prescription parameters of the mortar mixture, thefive-factor experiment with fine aggregate and the filler with a low modulus of elasticity, disperse polymeric powders andcellulose ethers, a polymer fiber for microdispersed reinforcement has been used. The obtained data indicate that the proposedapproach enables to obtain plaster mortars with physic mechanical characteristics that provide optimal working conditions“masonry - plaster coatings”.


2016 ◽  
Vol 2016 ◽  
pp. 1-17 ◽  
Author(s):  
Songlin Yue ◽  
Yanyu Qiu ◽  
Pengxian Fan ◽  
Pin Zhang ◽  
Ning Zhang

Analogue material with appropriate properties is of great importance to the reliability of geomechanical model test, which is one of the mostly used approaches in field of geotechnical research. In this paper, a new type of analogue material is developed, which is composed of coarse aggregate (quartz sand and/or barite sand), fine aggregate (barite powder), and cementitious material (anhydrous sodium silicate). The components of each raw material are the key influencing factors, which significantly affect the physical and mechanical parameters of analogue materials. In order to establish the relationship between parameters and factors, the material properties including density, Young’s modulus, uniaxial compressive strength, and tensile strength were investigated by a series of orthogonal experiments with hundreds of samples. By orthogonal regression analysis, the regression equations of each parameter were obtained based on experimental data, which can predict the properties of the developed analogue materials according to proportions. The experiments and applications indicate that sodium metasilicate cemented analogue material is a type of low-strength and low-modulus material with designable density, which is insensitive to humidity and temperature and satisfies mechanical scaling criteria for weak rock or soft geological materials. Moreover, the developed material can be easily cast into structures with complex geometry shapes and simulate the deformation and failure processes of prototype rocks.


1974 ◽  
Vol 96 (1) ◽  
pp. 44-46
Author(s):  
C. K. McDonald ◽  
R. E. McDonald

The effect of large displacements on the flexural edge stresses in thin cylindrical shells with flat head closures subjected to axisymmetric loads is considered. Results are presented which show that neglecting this nonlinear effect leads to nonconservative results. However, it is shown that these effects can usually be safely neglected except for very thin shells or for shells with a low modulus of elasticity. Curves are given which illustrate this effect for selected shell parameters.


2018 ◽  
Vol 14 (1) ◽  
pp. 126-135
Author(s):  
Reza Mirzaei ◽  
Naser Zarifmoghaddam

 Concrete as the most used material, is known as an integral part of construction. So far, many studies have been done in the field of improving the quality of concrete that most of them have examined change in concrete mix which is called concrete mix plan. However, the use of additives and also replacing commonly used materials in concrete with new materials always has been noteworthy. In this study, description of tests that have been done on fiber reinforced concrete will be discussed. Also, the condition of concrete mix plan will be discussed. Comparison between results of the tests showed that Forta reinforced concretes have more compressive, flexural and tensile strength and modulus of elasticity than normal and ordinary concretes.Journal of the Institute of Engineering, 2018, 14(1): 126-135 


Author(s):  
Tu T. Nguyen ◽  
Pham Thanh Tung ◽  
Kobir Hossain

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.


Copper slag is a rough blasting grit or a by-product acquired by the process of copper smelting and refining. These copper slags are recycled for copper recovery. In this paper, we analysed copper slag’s feasibility and evaluate its total competence in M25 grade concrete. In this observation, a concrete mixture is applied with copper slag as a fine aggregate ranging from 0%, 20%, 40%, 60%, 80%, and 100% respectively. The strength of copper slag’s implementation is accomplished on the basis of concrete’s flexural strength, compressive strength and splitting tensile strength. From the obtained results, in concrete 40% percentage of copper slag is used as sand replacement. On 28 days, the modulus of elasticity increased up to 32%, the compressive strength increased up to 34% and flexural strength is increased to 6.2%. From this experiment, it is proved technically that replacing sand using copper slag as a fine mixture in M25 grade concrete.


2016 ◽  
Vol 4 (2) ◽  
Author(s):  
Wayan Mustika ◽  
I M. Alit K. Salain ◽  
I K. Sudarsana

Nickel slag is one kind of nickel ore smelting waste after the combustion process. Production of nickel slag PT. Antam Pomalaa Kolaka Southeast Sulawesi province during the period 2011-2012 period approximately 1 million tons of slag / year, with a nickel content in ore processing of nickel is between 1.80% to 2.00%. Visually, the physical form of this nickel slag aggregate resembles. Research on the use of nickel slag as an aggregate in concrete mixture is carried out using a cylindrical specimen with a diameter of 15 cm and 30 cm high by 48 pieces were tested at 28 days with some variations in the mix. Variation 01, 100% natural aggregate, variation 02, nickel slag as coarse aggregate, variation 03, nickel slag as fine aggregate, and variation 04, nickel slag as coarse aggregate and fine aggregate. Aggregate gradation in the mixture is set and is designed so that it meets the specifications gradation mix for maximum aggregate size of 40 mm. The composition of the concrete mixture used is a mixture of concrete with the ratio of cement : fine aggegate : coarse aggregate is 1: 2: 3 in a weight ratio with cement water ratio (fas) is set at 0.5. The results showed that when compared with the use of natural agregate, terak nickel is used only as a coarse agregate, a fine agregate only and combined agregate coarse and fine agregates resulting slump values ??fell 39.47%, an increase of 55.26%, and an increase of 34.21%. As a coarse agregate, terak nickel increases the compressive strength, modulus of elasticity and splitting tensile strenght, respectively for 42.27%, 19.37% and 23.46%. As fine agregate, nickel terak resulting value of compressive strength, modulus of elasticity and tensile strength divided down respectively by 16.75%, 6.70% and 24.58%. As a combination of coarse and fine agregate, terak nickel increases the compressive strength, modulus of elasticity and splitting tensile strenght, respectively for 10.31%, 9.26% and 6.70%.  


2016 ◽  
Vol 677 ◽  
pp. 292-297 ◽  
Author(s):  
Tereza Pavlů ◽  
Magdaléna Šefflová ◽  
Vladimír Hujer

The main aim of this contribution is verification of properties of concrete with partial replacement of cement by recycled cement powder originating from waste concrete. The main topic of this article is the study of influence of partial replacement of cement by recycled cement powder (RCP) to the cement paste properties, workability of fresh concrete and strength development and dynamic modulus of elasticity of fine aggregate concrete with partial replacement of cement. The workability of fresh concrete were tested by flow table test. The compressive strength, tensile strength in bending and dynamic modulus of elasticity were tested at the age 7, 14, 28 and 90 days. Partial replacement of cement was 0, 5, 10 and 15 % for all these tests. Mechanical properties were investigated by using cubic and prismatic specimens. The determination of the initial setting time of cement paste were measured by automatic Vicat apparatus for replacement rate of cement 0, 5, 10, 15 and 25 %.


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