Structure and Mechanical Properties of Portland Cement-Polyacrylnitril Fiber Composites

1987 ◽  
Vol 114 ◽  
Author(s):  
I. Odler
Keyword(s):  
Mechanical Properties ◽  
Composite Materials ◽  
Portland Cement ◽  
Fracture Mechanism ◽  
Cement Composite ◽  
Fiber Composites ◽  
Cement Composites ◽  
Cement Ratio ◽  
Variable Water ◽  
Pan Fibers

ABSTRACTA series of fiber-cement composite materials was prepared by dispersing different amounts of polyacrylnitril (PAN) fibers in portland cement suspensions of variable water/solid ratios. The samples were used to study the effect of the volume of fibers and the water-cement ratio on the physico-mechanical properties of the material. The distribution of the fibers within the cementitious matrix and the fracture mechanism were studied by SEM and compared with those existing in glass fiber-cement composites.

Preparation and Mechanical Properties of Polyethylene-Portland Cement Composites

2009 ◽  
Vol 1242 ◽  
Author(s):  
Rivas-Vázquez L.P. ◽  
Suárez-Orduña R. ◽  
Valera-Zaragoza M. ◽  
Máas-Díaz A. De la L. ◽  
Ramírez-Vargas E.
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Portland Cement ◽  
Plastic Waste ◽  
Cement Composites ◽  
Compression Tests ◽  
Standard Samples ◽  
Cement Ratio ◽  
Reinforcing Fibers ◽  
Waste Polyethylene

ABSTRACTThe effects of waste polyethylene aggregate as admixture agent in Portland cement at different addition polyethylene/cement ratios from 0.0156 to 0.3903 were investigated. The reinforced samples were prepared according the ASTM C 150 Standard (samples of 5 × 5 × 5 cm). The reinforcing fibers were milling at a size of 1/25 in diameter, form waste and used them to evaluate the effects in mechanical properties in cement-based composites. The evaluation of polyethylene as additive was based on results of density and compression tests. The 28-day compressive strength of cement reforced with plastic waste at a replacement polyethylene/cement ratio of 0.0468 was 23.5 MPa compared to the control concrete (7.5 MPa). The density of cement replaced with polyethylene varies from 2.114 (0% polyethylene) to 1.83 g/cm3 by the influence of polyethylene.

The Study of the Processes of Structure Formation in the System "Portland Cement-Carbon Nanotubes-Surfactant" from the Point of View of Physicochemical Mechanics of Dispersed Systems

2020 ◽  
Vol 864 ◽  
pp. 158-163
Author(s):  
Kateryna Pushkarova ◽  
Andrii Plugin ◽  
Maryna Sukhanevych
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Composite Materials ◽  
Portland Cement ◽  
Structure Formation ◽  
Point Of View ◽  
Cement Composites ◽  
Dispersed Systems ◽  
Physicochemical Mechanics ◽  
The Relationship

The article presents the studies of the processes of structure formation in the system "cement-plasticizer - crude carbon nanotubes", established the relationship with the parameters of the structure, physical-mechanical and operational properties of composite materials from the standpoint of physicochemical mechanics of dispersed systems and shows the influence of processes on the physical-mechanical properties of cement composites.

Effects of Quarry Dust as Partial Sand Replacement on Compressive Strength and Crack Profile of Cement Composites

2015 ◽  
Vol 819 ◽  
pp. 399-404
Author(s):  
M. Madzura ◽  
M.N. Mazlee ◽  
Shamsul Baharin Jamaludin
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Cement Composite ◽  
Cement Composites ◽  
Cement Ratio ◽  
Water Cement Ratio ◽  
Strength Tests ◽  
Experimental Works ◽  
Quarry Dust ◽  
Crack Profile

This research presents the findings of experimental works in terms of mechanical properties and crack profile of cement composites containing quarry dust at different percentages as a partial sand replacement. The compositions of quarry dust were varied from 10 to 20 wt. % and were mixed into five different ratios. It was found that 0.45 water cement ratio was suitable to mix all proportions and values of slump were observed have been increased with the increasing percentage of quarry dust in cement composites. The compressive strength tests were carried out and the results showed that the compressive strength decreased at each 2.5 percent interval of quarry dust at 7 and 28 days of curing. However, the strength developments of cement composites were increased corresponding to the ages of curing. The crack profiles of cement composites have been analyzed to investigate the strength developments of the cement composites. According to the results, the cracks in the specimens were in shearing pattern at 10 and 12.5 wt. % of quarry dust in cement composites. Meanwhile, as the contents of quarry dust at 15, 17.5 and 20 wt. %, the specimens failed in shearing and splitting patterns. According to the findings of compressive strength and crack profile, the contents of quarry dust as a partial sand replacement is 12.5 wt. % were more suitable to be utilized in cement composite

scholarly journals Influence of nanocellulose on the hydration process of Portland cement and concrete properties

2020 ◽  
Vol 17 (5) ◽  
pp. 155-160
Author(s):  
V. I. Khirkhasova ◽  
Keyword(s):  
Mechanical Properties ◽  
Portland Cement ◽  
Physical And Mechanical Properties ◽  
Cement Composite ◽  
High Density ◽  
Strength Characteristics ◽  
New Method ◽  
Concrete Properties ◽  
Hardening Process ◽  
Study Results

The paper deals with modification of cement composite and concrete with nanocellulose in low and high density. The author presents the study results of the influence of nanocellulose on the cement composite hardening process, as well as the physical and mechanical properties of heavy concrete. The influence of the used additive on the rheological and strength characteristics of concrete is revealed. A new method is proposed to improve the material performance.

scholarly journals DESIGN OF CEMENT COMPOSITES WITH INCREASED IMPERMEABILITY

Vestnik MGSU ◽  
2016 ◽  
pp. 72-81
Author(s):  
Roman Sergeevich Fedyuk
Keyword(s):  
Composite Materials ◽  
Cement Composite ◽  
Vapor Permeability ◽  
Cement Stone ◽  
Cement Composites ◽  
Hydrated Cement ◽  
Body Density ◽  
Scale Levels ◽  
Positive Effect ◽  
Improved Characteristics

The paper deals with the development of composite binders for producing concrete with improved characteristics of gas, water and vapor permeability. The authors investigate the processes of composite materials formation in order of decreasing scale levels from macro to nanostructures. The criteria for optimization of the volume of dispersed additives in concrete are offered. The authors theoretically studied the technological features of the formation of hydrated cement stone structure. A positive effect of nanodispersed additives on the structure and physico-mechanical properties of cement composite materials are predicted. Thanks to its improved features, such as good ratio of strength and body density, high density and lifetime, the modified concrete may be used when solving various practical tasks of the construction branch.

scholarly journals Properties of cement composites based on limestone depending on their granulometric composition

Vestnik MGSU ◽  
2020 ◽  
pp. 999-1006
Author(s):  
Svetlana V. Samchenko ◽  
Olga V. Alexandrova ◽  
Anton Yu. Gurkin
Keyword(s):  
Composite Materials ◽  
Portland Cement ◽  
Granulometric Composition ◽  
Coarse Grained ◽  
Cement Matrix ◽  
Cement Composites ◽  
Construction Costs ◽  
Initial Strength ◽  
Fine Grained ◽  
Additional Formation

Introduction. The use of limestone in cement compositions as an additional cementing agent solves both environmental and economic problems, namely, reduction of construction costs. In this regard, the study of the properties of the granulometric composition and volumetric content of cement composites, containing limestone, becomes increasingly important. The mission of this research is to optimize the properties of composite materials containing Portland cement and limestone by changing the granulometric composition of flour limestone. Materials and methods. Limestone, having three different Blaine milling fineness values of 250, 300 and 450 m2/kg, was used; its content reached 10, 15, 25 and 35 %. Cement and sand mortars were applied for testing purposes. The influence of the granulometric composition of limestone on the workability and compressive strength of composite cement was determined. Results. The effect of limestone on the limit shear stress becomes more pronounced when the amount of limestone increases to 25 and 35 %. This is most noticeable for limestone with a high content of fine fractions of 5–20 µm. The use of finely milled limestone increases the initial strength of the composite material. By adding 10 and 15 % of such limestone we can increase the strength by 16–20 %, and supplementary 25–35 % of limestone increases strength by 5–8 %. Strength enhancement is due to the reactivity of limestone and formation of calcium hydrocarbon aluminate 3CaO∙Al2O3∙СаСО3∙12H2O, which promotes formation of the crystal framework of the cement matrix. Additional formation of crystalline hydrates in the initial coagulation structure deteriorates the mortar workability, but increases its strength. Conclusions. The use of coarse-grained limestone significantly improves mortar workability, while the use of fine-grained limestone increases its content without reducing its strength. The granulometric composition of ground limestone shall be as close as possible to the granulometric composition of cement for the properties of composite materials containing Portland cement and limestone to be optimized.

EFFECT OF STYRENE-BUTADIENE COPOLYMER (SBR) LATEX ON MECHANICAL AND TRANSPORT PROPERTIES OF PORTLAND CEMENT MORTAR

2020 ◽  
Vol 15 (4) ◽  
pp. 185-197
Author(s):  
Daniel Hatungimana ◽  
Şemsi Yazici ◽  
Şevket Orhan ◽  
Ali Mardani-Aghabaglou
Keyword(s):  
Mechanical Properties ◽  
Portland Cement ◽  
Detrimental Effect ◽  
Cement Mortar ◽  
Styrene Butadiene Rubber ◽  
Butadiene Rubber ◽  
Replacement Level ◽  
Cement Production ◽  
Cement Ratio ◽  
Styrene Butadiene

ABSTRACT Portland cement is extensively used as a binder in concrete production. However, with Portland cement production, 5% of the natural resources used in this production are consumed, constituting 5–7% of the total CO2 emission. In order to mitigate the environmental problems associated with cement production, styrene-butadiene rubber latex was used as cement replacement up to 20%. In this study, compressive strength, flexural strength, unit weight, water absorption, open porosity, water sorptivity and the chloride ion permeability of Portland cement mortar mixtures modified by styrene-butadiene rubber (SBR) polymeric latex were investigated. For this purpose, the sand/cement ratio and the water/cement ratio were kept constant as 3/1 and 0.5, respectively. In addition to the control mixture containing no polymer, 1, 2, 3, 5, 10 and 20 wt.% of cement was replaced with SBR. In this way, seven mortar mixtures were prepared. Mixed curing (wet cure and dry cure) method was applied to the mortar specimens. Results showed that up to a 5% replacement level, it is possible to improve the mechanical properties of cement mortars with SBR latex addition. However, at a 10% and 20% replacement level, SBR had a significant detrimental effect on the mechanical properties of polymer modified mortars. However, the transport properties decreased with the incorporation rate of SBR latex and the detrimental effect of SBR replacement was more pronounced in 20% SBR mortar mixtures.

Reinforced Cement Composites – Effect of Hybrid Fibres on Selected Properties

2015 ◽  
Vol 824 ◽  
pp. 179-183
Author(s):  
Dana Koňáková ◽  
Eva Vejmelková
Keyword(s):  
Mechanical Properties ◽  
Thermal Loading ◽  
Bending Strength ◽  
Linear Thermal Expansion Coefficient ◽  
Linear Thermal Expansion ◽  
Cement Composite ◽  
Polypropylene Fibre ◽  
Cement Composites ◽  
Matrix Density ◽  
Reinforced Cement

In this article selected properties of a glass and polypropylene fibre reinforced cement composite materials are studied. They are determined either after preceding thermal treatment or during thermal loading. Basic physical properties (in concrete terms bulk density, matrix density and open porosity), mechanical properties (in concrete terms tensile strength and bending strength) are determined after subjecting the specimens to the pre-heating temperatures of 600°C, 800°C and 1000°C. The linear thermal expansion coefficient is measured directly as functions of temperature up to 1000°C. The critical temperature for the glass and polypropylene fibre reinforced cement composite when most properties are worsening in a significant way is found apparently 500°C.

Effects of Fly Ash Addition on Compressive Strength and Flexural Strength of Foamed Cement Composites

2013 ◽  
Vol 795 ◽  
pp. 664-668 ◽  
Author(s):  
Roshasmawi Abdul Wahab ◽  
Mohd Noor Mazlee ◽  
Shamsul Baharin Jamaludin ◽  
Khairul Nizar Ismail
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Fly Ash ◽  
Flexural Strength ◽  
Cement Composites ◽  
Volume Percent ◽  
Foaming Agent ◽  
Cement Ratio ◽  
Water To Cement Ratio

In this study, the mixing of polystyrene (PS) beads and fly ash as a sand replacement material in foamed cement composites (FCC) has been investigated. Specifically, the mechanical properties such as compressive strength and flexural strength were measured. Different proportions of fly ash were added in cement composites to replace the sand proportion at 3 wt. %, 6 wt. %, 9 wt. % and 12 wt. % respectively. The water to cement ratio was fixed at 0.65 meanwhile ratios of PS beads used was 0.25 volume percent of samples as a foaming agent. All samples at different mixed were cured at 7 and 28 days respectively. Based on the results of compressive strength, it was found that the compressive strength was increased with the increasing addition of fly ash. Meanwhile, flexural strength was decreased with the increasing addition of fly ash up to 9 wt. %. The foamed cement composites with 12 wt. % of fly ash produced the highest strength of compressive strength meanwhile 3 wt. % of fly ash produced the highest strength of flexural strength.

Influence of Silica Based Carbon Nano Tube Composites in Concrete

2017 ◽  
Vol 26 (1) ◽  
pp. 096369351702600
Author(s):  
BLP Dheeraj Swamy ◽  
Vaibhav Raghavan ◽  
K Srinivas ◽  
K Narasinga Rao ◽  
Mahadevan Lakshmanan ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Mechanical Performance ◽  
Cement Mortar ◽  
Cement Composite ◽  
Small Scale ◽  
Cement Composites ◽  
Potential Candidate ◽  
Carbon Nano Tube ◽  
Portland Cement Paste

This study focuses on the utilization of highly densified materials in cementitious composites with objectives of improving the mechanical performance and minimizing the number and size of defects. Due to their excellent mechanical properties, carbon nanotubes (CNTs) are now viewed as potential candidate for reinforcement in cement composites. The present paper reports the use of carbon nanotubes (CNTs) as reinforcement to improve the mechanical properties of portland cement paste and creating multifunctional concrete. In order to increase the bonding, and strength, a material with intermediate fineness, highly densified silica fumes, was also utilized. The densified silica fumes along with CNT are added to cement mortar in various proportions. Small-scale specimens were prepared to measure the mechanical properties as a function of nanotube concentration and distribution. Furthermore, properties like shrinkage, permeability and alkalinity of the resultant composite were also investigated. The study addresses the significance of CNT as an additive to the enhancement of properties of cement composite.

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