Extreme Modelling of Concrete Optimal Composition and Content of the Components

2021 ◽  
Vol 887 ◽  
pp. 536-541
Author(s):  
N.P. Lukuttsova ◽  
A.A. Pykin ◽  
S.N. Golovin ◽  
P.A. Artamonov
Keyword(s):  
Compressive Strength ◽  
Water Absorption ◽  
Bending Strength ◽  
Cement Content ◽  
Halloysite Nanotubes ◽  
Particle Sizes ◽  
Computing Environment ◽  
Fine Grained ◽  
Fiber Concrete ◽  
Micro Level

The optimal compositions of fine-grained concrete (FGC) with two-level reinforcement with fiber are determined via the extreme modelling of experimental data based on the Scilab engineering and scientific computing environment. At the macro level brass plated fibre of the wave profile FSW LV 15/0.3 made of steel grade 70-85 with the fiber length of 15 mm and the diameter of 0.3 mm was used for reinforcement. At the micro-level the halloysite nanotubes NN-RTE 200 with the particle sizes from 0.05 to 5 microns were applied. Having calculated the models the designed program Extr.sce determined the extrema of the required characteristics of fine-grained concrete Max_z and their coordinates max_x and max_y, corresponding to the contents of the brass plated fiber (x) and halloysite nanotubes additive (y). The graphic dependences of the compressive strength, bending strength and water absorption of fine-grained fiber concrete on the content of brass plated fibre and halloysite nanotubes additive with minimum, average and maximum cement content in it in the form of contour and 3d graphs of the interpolation surface are obtained. Two-level reinforcement of FGC, optimized by the program Extr.sce, proved that fine-grained concrete with 10% of brass plated fibre, 20% of halloysite nanotubes additives, and cement content of 600 kg had the maximum compressive strength of 70.26 MPa. In order to obtain FGC with maximum bending strength (17.43 MPa), there should be 5% of brass plated fibre, 10% of halloysite nanotubes additives, and 600 kg of cement in it. The fine-grained concrete without any reinforcement additives will have the minimum water absorption (3%).

scholarly journals CERAMIC WASTE REUSABILITY: EFFECT OF AGGREGATE GRAIN SIZE AND MIX RATIO ON LIGHTWEIGHT DENSE MASONRY UNIT PRODUCTION

2019 ◽  
pp. 3-12
Author(s):  
Ademola Ayodeji Ajayi-Banji ◽  
D. A. Jenyo ◽  
Jubril Bello ◽  
M. A. Adegbile
Keyword(s):  
Compressive Strength ◽  
Water Absorption ◽  
Management Practices ◽  
Absorption Capacity ◽  
Ceramic Ware ◽  
Fine Aggregate ◽  
Particle Sizes ◽  
Masonry Unit ◽  
Water Absorbability ◽  
Masonry Units

Ceramic ware waste generation is becoming a global concern because of the increasing volume, hazardous nature, limited reusability, and poor waste management practices. This study examined the feasibility and efficacy of the inclusion of this waste as complementary aggregate in solid masonry unit production with bias interest on the compressive strength and water absorbability. Three particle sizes (1.4, 1.7, and 2.0 mm) of crushed ceramic ware waste were blended with natural fine aggregate under three different mix ratios (10, 20, and 30%) to produce the masonry units cured for 7, 14, 21, and 28 days prior to compressive tests analysis. Afterwards, some of the categories cured for 28-days were subjected to water absorption test. Morphology and elemental composition of the aggregates were also inspected using SEM-EDM machine. Also investigated were some of the aggregates’ physical properties. Results indicated that most of the waste-modified solid masonry units not only had water absorption capacity within required standard. The values were equally lower than the unmodified dense block (control) by 27 - 50%. Of the eighteen different categories produced, all M20T14, M20T21, and M30T28 modified dense masonry unit series with P1.7 (1.7 mm) and P2.0 (2.0 mm) particle sizes had high crushing force, compressive strength, and modulus range, which were 57 - 70 kN, 57 - 61 kN, 59 - 76 kN; 5.1 - 5.2 MPa, 5.1 - 5.5 MPa, 5.3 – 6.8 MPa; and 400 – 441 MPa, 411 – 419 MPa, 468 – 480 MPa respectively. Hence, modified masonry units with particle sizes P1.7 and P2.0 under the M20T14, M20T21, and M30T28 series are suitable masonry units for non-loading construction purposes. Interestingly, modified masonry unit (M30P2.0T7) cured under 7 days could also fit into this category. Hence, utilization of ceramic ware waste as co-aggregate in dense masonry units with M20 and M30 series production were established in this study for non-loading construction purposes

scholarly journals Influence of Steel and Polypropylene Fibers Addition on Selected Properties of Fine-Grained Concrete

2018 ◽  
Vol 28 (4) ◽  
pp. 138-148
Author(s):  
Arkadiusz Denisiewicz ◽  
Tomasz Socha ◽  
Krzysztof Kula ◽  
Marcin Pasula
Keyword(s):  
Physical Properties ◽  
Laboratory Tests ◽  
Bending Strength ◽  
Polypropylene Fibers ◽  
Fine Grained ◽  
Concrete Mixtures ◽  
Mechanical And Physical Properties ◽  
Fiber Concrete ◽  
Degree Of Reinforcement ◽  
Water Tightness

Abstract The article presents results of laboratory tests of selected mechanical and physical properties of fine-grained fiber concrete. Tests were conducted on samples with a different degree of reinforcement made on the basis of steel and polypropylene fibers. For the designed concrete mixtures and prepared samples, slump class, shrinkage, compressive and bending strength and water tightness were determined.

scholarly journals Recycling of waste incineration bottom ash in the production of interlocking concrete bricks

2021 ◽  
Vol 15 (2) ◽  
pp. 101-112
Author(s):  
Nguyen Huu May ◽  
Huynh Trong Phuoc ◽  
Le Thanh Phieu ◽  
Ngo Van Anh ◽  
Chau Minh Khai ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Water Absorption ◽  
Bending Strength ◽  
Bottom Ash ◽  
Waste Incineration ◽  
Engineering Properties ◽  
Fine Aggregate ◽  
Test Results ◽  
Toxic Material ◽  
Visible Defect

This study presents an experimental investigation on the recycling of waste incineration bottom ash (IBA) as a fine aggregate in the production of interlocking concrete bricks (ICB). Before being used, the concentration of heavy metal in IBA was determined to confirm it is a non-toxic material. In this study, the IBA was used to replace crushed sand (CSA) in the brick mixtures at different replacement levels of 0%, 25%, 50%, 75%, and 100% (by volume). The ICB samples were checked for dimensions, visible defects, compressive strength, bending strength, water absorption, and surface abrasion in accordance with the related Vietnamese standards. The test results demonstrated that the IBA used in this study was a non-toxic material, which can be widely used for construction activities. All of the ICB samples prepared for this study exhibited a nice shape with consistent dimensions and without any visible defects. The incorporation of IBA in the brick mixtures affected engineering properties of the ICB samples such as a reduction in the compressive strength and bending strength and an increment in water absorption and surface abrasion of the brick samples. As a result, the compressive strength, bending strength, water absorption, and surface abrasion values of ICB samples at 28 days were in the ranges of 20.6 – 34.9 MPa, 3.95 – 6.62 MPa, 3.8 – 7.2%, and 0.132 – 0.187 g/cm2, respectively. Therefore, either partial or full replacement of CSA by IBA, the ICB with grades of M200 – M300 could be produced with satisfying the TCVN 6476:1999 standard in terms of dimensions, visible defects, compressive strength, water absorption, and surface abrasion. These results demonstrated the high applicability of the local IBA in the production of the ICB for various construction application purposes. Keywords: interlocking concrete brick; waste incineration bottom ash; visible defect; compressive strength; bending strength; water absorption; surface abrasion.

scholarly journals BRIEF EVALUATION OF MASS LOSS INDEX, WATER ABSORPTION AND COMPRESSIVE STRENGTH REVERTIBILITY COEFFICIENTS OF PAPERBRICKS IMMERSED IN WATER

2015 ◽  
pp. 24-30
Author(s):  
Akinwande Abayomi
Keyword(s):  
Weight Loss ◽  
Compressive Strength ◽  
Mass Loss ◽  
Water Absorption ◽  
Cement Content ◽  
Sand Content ◽  
Loss Index

With the need to develop alternative, lightweight cheaper bricks for masonry which will be durable, paperbrick produced with varying cement content of 3 – 18 wt. % and fixed sand content of 20 wt. % were immersed in water for seven days, it was observed that with increasing cement content and curing ages, compressive strength revertibility increased. Weight loss index also reduced with higher cement content and longer curing days and concluded that higher cement content and longer duration periods produce more water durable paperbricks.

scholarly journals EFFECT OF MICROFILLERS BASED ON NATURAL WOLLASTONITE ON PROPERTIES OF FINE-GRAINED CONCRETE

2020 ◽  
pp. 20-28 ◽  
Author(s):  
E. Karpikov ◽  
N. Lukutcova ◽  
G. Soboleva ◽  
S. Golovin ◽  
Yu. Cherenkova
Keyword(s):  
Anionic Surfactant ◽  
Ball Mill ◽  
Bending Strength ◽  
Particle Diameter ◽  
Cement Stone ◽  
Particle Sizes ◽  
Ultrasonic Dispersion ◽  
Fine Grained ◽  
Amorphous Nature ◽  
Type C

The possibility of obtaining effective highly dispersed additives from natural wollastonite is substantiated and their influence on the properties of fine-grained concrete is investigated. On the basis of wollastonite, a complex micro-filler with particle sizes up to 100 microns was developed, obtained by joint grinding with quartz sand in a 3:1 ratio in a ball mill in the presence of an anionic surfactant naphthalene-formaldehyde type C-3 and a calcium stearate hydrophobizer technical C-17. A suspension of wollastonite with a modal particle diameter of 405 nm was obtained by pre-grinding wollastonite and anionic surfactant in a ball mill, with their further ultrasonic treatment in a bath-type activator. Mathematical models of the dependence of compression and bending strength on the content of the initial components are developed. It is established that the complex microfill leads to an increase in the strength of fine-grained concrete in bending by 2 times, in compression by 1.7 times with its content in the composition of fine-grained concrete in the amount of 10% by weight of cement. Wollastonite suspension increases the bending strength of fine-grained concrete to 3.1 MPa, compression to 57.8 MPa. The results of qualitative x-ray phase analysis showed that the total intensity of diffraction maxima of not fully hydrated alite C3S, belite C2S grains and their aggregates in cement stone with wollastonite decreases by 1.5-2 times compared to the control composition. This is most likely due to the amorphous nature of the wollastonite surface after grinding in a ball mill and ultrasonic dispersion in a bath-type activator. In addition, such particles are the centers of crystallization. Their needle-like shape contributes to the reinforcement of the structure by crystallizing new formations of cement stone.

Effect of Curing Condition on Some Properties of Cement Stabilized Lateritic Interlocking Bricks

2013 ◽  
Vol 824 ◽  
pp. 37-43 ◽  
Author(s):  
Manasseh Joel ◽  
Joseph E. Edeh
Keyword(s):  
Compressive Strength ◽  
Water Absorption ◽  
Conventional Method ◽  
Cement Content ◽  
Soil Classification ◽  
Curing Conditions ◽  
Curing Condition ◽  
Condition C

The effect of three different curing conditions on the compressive strength and water absorption of lateritic interlocking bricks, produced with laterite stabilized with 0 %, 2 %, 4 %, 6 % and 8 % cement content was investigated. The study is aimed at providing an alternative to the conventional method of curing interlocking bricks. The three curing conditions used in the study are A (covering of bricks with tarpaulin after sprinkling with water twice a day) B (complete immersion in water) C (complete covering with air and water tight polythene bags). Laterite used in the production of interlocking bricks was as an A-2-7 soil, using the AASHTO system of soil classification. Compressive strength of bricks increased with cement content and days under the different curing conditions, 28 day optimum compressive strength values of 4.28 N/mm2, 3.67 N/mm2 and 3.67 N/mm2 at 8 % cement content was obtained from bricks using curing condition C B and A respectively. Water absorption value decreased with cement content under the different curing conditions, minimum water absorption values of 2.44 %, 1.68 % and 1.72 % at 8 % cement content was obtained with bricks cured under curing condition A B and C respectively. Based on results of test, curing condition C is recommended for use in the production of cement stabilized interlocking bricks, as this will enhance effective production of interlocking bricks in areas where water is scarce.

Functional properties of foam concrete with ultra-small additives of carbon nanotubes

2021 ◽  
Vol 1 ◽  
pp. 49-57
Author(s):  
R. D. Sldozyan ◽  
◽  
A. G. Tkachev ◽  
Z. A. Mikhaleva ◽  
A. E. Burakov ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Compressive Strength ◽  
Portland Cement ◽  
Water Absorption ◽  
Bending Strength ◽  
Testing Machine ◽  
Control Sample ◽  
Strength Increase ◽  
Foam Concrete ◽  
High Concentrations

We studied the properties of foam concrete based on Portland cement, modified with of the ultra-low concentration carbon nanotubes addition. Carbon nanotubes (Taunit-24) with a mass percentage of 0.0004, 0.0006, 0.0008, 0.001 and 0.0012 % by weight of cement were used for the dispersed reinforcement of foam concrete based on Portland cement. To determine of the modified concrete samples strength characteristics an IP-M testing machine was used. The results of the study showed that the use of the carbon nanotubes additives in concentrations of 0.0004, 0.0006, 0.0008 % allows to gradually increase the compressive strength compared to the control sample. The compressive strength increase on 1, 12.4 and 68 %, respectively, and gradually decreases at concentrations of 0.001 and 0.0012 % from 55.5 to 45.7 %, respectively. A positive effect of the carbon nanotubes additive (0.0004, 0.0006 and 0.0008 %) is also noted when testing the bending strength by 3.7, 13.7 and 33.7%, respectively. With a further increase in the additive content (0.001 and 0.0012 %), the strength decreases to 20 and 14.8 %, respectively. When assessing water absorption, a decrease was showed with additives with concentrations of 0.0004 and 0.0006 %. However, at high concentrations of additives (0.0008, 0.001 and 0.0012 %), the highest percentage of water absorption was established.

Preparation and properties of melamine-formaldehyde rigid closed-cell foam toughened by ethylene glycol/carbon fiber

2020 ◽  
pp. 026248932092923
Author(s):  
Chunhui Li ◽  
Haihong Ma ◽  
Zhengfa Zhou ◽  
Weibing Xu ◽  
Fengmei Ren ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Thermal Stability ◽  
Compressive Strength ◽  
Water Absorption ◽  
Cellular Structure ◽  
Bending Strength ◽  
Melamine Formaldehyde ◽  
Cell Ratio ◽  
Closed Cell ◽  
Rigid Foams

Toughing melamine-formaldehyde (MF) rigid closed-cell foams were prepared by using ethylene glycol (EG) and carbon fiber (CF) as composite toughening agents. The pulverization rate, compressive strength, bending strength, cellular structure, closed-cell ratio, water absorption ratio, thermal conductivity, thermal stability, limiting oxygen index (LOI), and char yield were characterized to study the morphology, mechanical, thermal, and fire-retardant properties of as-prepared toughing MF rigid foams. The pulverization rate result showed that introduction of composite modifier can obviously improve the toughness of MF rigid foams. The cellular structure, closed-cell ratio, and water absorption results showed that the addition of EG/CF can increase the closed-cell ratio and control the cell size of MF rigid foams. The compressive strength and bending strength results showed that the incorporation of composite modifier of MF rigid foams dramatically improved the mechanical properties. The LOI, char yield, and thermal stability results showed that the toughing MF rigid foams remained more intact char skeleton with flame-retardant effect, thus reducing the fire hazards. The as-prepared toughing MF rigid foams showed the best comprehensive performance with pulverization rate of 5.21%, compressive strength of 355.3 kPa, bending strength of 0.44 MPa, closed-cell ratio of 79.1%, water absorption of 9%, thermal conductivity of 0.031 W m−1 K−1, and LOI of 39.6%. Compared with unmodified MF rigid foams, toughing rigid closed-cell MF foams possess excellent pulverization rate, compressive strength, bending strength, cellular structure, thermal insulation, and flame retardancy.

scholarly journals DEVELOPMENT OF CHICKEN FEATHER REINFORCED INSULATION PAPERBOARD FROM WASTE CARTON AND PORTLAND CEMENT

2019 ◽  
Vol 16 (1) ◽  
pp. 44
Author(s):  
Odusote Jamiu Kolawole ◽  
Dosunmu Kayode Stephen
Keyword(s):  
Thermal Conductivity ◽  
Compressive Strength ◽  
Portland Cement ◽  
Water Absorption ◽  
Modulus Of Elasticity ◽  
Cement Content ◽  
Modulus Of Rupture ◽  
Chicken Feather ◽  
Thickness Swelling ◽  
Chicken Feathers

Cartons and chicken feathers are common wastes which we need to dispose in one way or another. Disposal problems associated with these wastes can be solved by processing them into useful products such as insulation and ceiling boards. In this study, chicken feather reinforced ceiling board was developed from waste carton and Portland cement. The quantity of the chicken feather was kept constant at 10% based on previous findings, while the cement and waste carton contents were varied to produce 5 samples of different compositions. The density of the board was found to range between 337.8 and 700.7 kg/m2, while the thickness swelling ranges between 0.81 and 9.02%. Water absorption values of the samples varied between 7.16 and 24.41%, while the compressive strength and modulus of elasticity values varied from 4.8 - 10.3 N/mm2 and 1.03 - 1.60 GPa, respectively. The values of modulus of rupture ranges between 1.34 and 2.2 MPa while the thermal conductivity of the samples ranges from 0.951 to 1.077 W/m.K. Density, compressive strength, modulus of elasticity, modulus of rupture and thermal conductivity of the samples increased as the cement content increased, while the thickness swelling and water absorption decreased with increase in cement content. The results revealed that the properties of ceiling boards developed from 80% cement, 10% carton and 10% chicken feather can compete favorably with most ceiling boards available in the market.

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