Study of Wet-Drying Cycles on Sisal, Jute and White Curaua Fibers on the Resistance Parameters of Cement-Based Composites

2018 ◽  
Author(s):  
Fernando Benedicto Mainier ◽  
Viktor Labuto Fragoso Sereno Ramos ◽  
Claudio Fernando Mahler
Keyword(s):  
Portland Cement ◽  
Cement Matrix ◽  
Cement Composites ◽  
Short Fibers ◽  
Direct Tension ◽  
Wetting And Drying ◽  
Bending Load ◽  
Curaua Fibers ◽  
Wetting And Drying Cycle

This study presents the results of the mechanical characterization of cement composites reinforced with short fibers of jute, sisal and curauá. Tests of direct tension in flexion and traction, after wetting and drying cycle (5 cycles) to determine the first crack were performed to determine the first crack, the tension and post-peak toughness and strengh of the composites. To ensure the the composite durability, the ordinary Portland cement matrix was modified by adding metakaolin, to consume the calcium hydroxide generated during Portland cement hydration. The composites were produced using short fibers of jute, sisal and curauá (50 mm) at levels of 2%, 4% and 6% of sisal and white curauá, and 3%, 6% and 9% to jute. The fibers of jute and white curauá employed in this study came from the Brazilian Amazon, while the sisal came from the Brazilian Northeast.This fibers have great economic importance in the producing region. Composites with high toughness, strength and multiple cracking processes under bending load were obtained when volume fractions equal to 3% of jute were used as reinforcement and when 6% of sisal and 4% of white curauá were used as reinforcement.

Mechanical Behavior of Jute Fiber-Cement Based Composites

2012 ◽  
Vol 517 ◽  
pp. 469-476 ◽  
Author(s):  
L.V. Carvalho ◽  
Ana Catarina J. Evangelista ◽  
Romildo Dias Toledo Filho
Keyword(s):  
Portland Cement ◽  
High Performance ◽  
Fiber Composites ◽  
Jute Fiber ◽  
Cement Matrix ◽  
Direct Tension ◽  
Bending Tests ◽  
Bending Load ◽  
Fracture Processes

This study presents the results of the mechanical characterization of short jute fiber cement mortar composites. Compression, direct tension and bending tests were performed to determine the first crack, post-peak strength, toughness and fracture processes of the composites. To ensure the composite durability, the ordinary Portland cement matrix was modified by adding metakaolin to consume the calcium hydroxide generated during Portland cement hydration. The composites were produced using reinforcement ratios of 2% and 3% of short jute fiber (25 mm) in a self-compacting matrix of maximum packing. Jute plant is easy to grow in the Amazon region of Brazil where arrived in early 30s coming from Asia and represents the main economic activity of the Amazon riverine population. The tensile behavior of this high performance natural reinforcement was determined in the present study using 30 mm long fiber. Composites with high toughness, strength and multiple cracking processes under bending load were obtained when volume fractions equal to 3% were used as reinforcement.

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.

Characterization of Cement-Rice Husk Ash Composites

2017 ◽  
Vol 866 ◽  
pp. 187-190
Author(s):  
Thossapon Jaihlong ◽  
Nittaya Jaitanong ◽  
Suparut Narksitipan
Keyword(s):  
Portland Cement ◽  
Rice Husk ◽  
Fiber Optic ◽  
Rice Husk Ash ◽  
Cementitious Materials ◽  
Cement Composites ◽  
X Ray Diffraction ◽  
X Ray ◽  
Lime Water

In present research, the cement-rice husk ash composites were prepared and characterized. The samples were added fiber optic and rice husk ash was used as replacement cementitious materials at 10, 20, 30 and 40 wt% of portland cement. The samples were demolded after 24 h casting and cured in saturated lime water for 3 days. After these periods, the samples were wrapped with plastics films for 7 and 28 days. Then, samples were dried in air for 24 h. The chemical compositin of portland cement and rice husk ash were characterized by using x-ray fluorence spectrometry (XRF). Additionally, dried samples were analysized phase compositions and crystalline structure by using x-ray diffraction (XRD) technique. The chemical element compositions and microstructure were detected by scanning electron microscopy (SEM), respectively. Moreover, The effect of rice husk ash in these cement composites were investigated in this research.

Multiple techniques of microstructural characterization of DEF: Case of study with high early strength Portland cement composites

2021 ◽  
Vol 311 ◽  
pp. 125341
Author(s):  
Kleber Franke Portella ◽  
Nicole Pagan Hasparyk ◽  
Mariana D'Orey Gaivão Portella Bragança ◽  
Jeferson Luís Bronholo ◽  
Bruna Gomes Dias ◽  
...  
Keyword(s):  
Portland Cement ◽  
Microstructural Characterization ◽  
Cement Composites ◽  
Early Strength

Polyaniline and magnetite on curaua fibers for molecular interface improvement with a cement matrix

2021 ◽  
Vol 1233 ◽  
pp. 130101
Author(s):  
Fernanda Veloso de Carvalho ◽  
Kaushik Pal ◽  
Fernando Gomes de Souza Junior ◽  
Romildo Dias Toledo Filho ◽  
Thuanny Moraes de Almeida ◽  
...  
Keyword(s):  
Cement Matrix ◽  
Curaua Fibers

scholarly journals The Influence of Cement Substitution by Biomass Fly Ash on the Polymer–Cement Composites Properties

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3079
Author(s):  
Beata Jaworska ◽  
Dominika Stańczak ◽  
Joanna Tarańska ◽  
Jerzy Jaworski
Keyword(s):  
Fly Ash ◽  
Building Materials ◽  
Raw Materials ◽  
Combustion Process ◽  
Biomass Combustion ◽  
Cement Composites ◽  
Cement Mortars ◽  
Mineral Additive ◽  
Biomass Fly Ash

The generation of energy for the needs of the population is currently a problem. In consideration of that, the biomass combustion process has started to be implemented as a new source of energy. The dynamic increase in the use of biomass for energy generation also resulted in the formation of waste in the form of fly ash. This paper presents an efficient way to manage this troublesome material in the polymer–cement composites (PCC), which have investigated to a lesser extent. The research outlined in this article consists of the characterization of biomass fly ash (BFA) as well as PCC containing this waste. The characteristics of PCC with BFA after 3, 7, 14, and 28 days of curing were analyzed. Our main findings are that biomass fly ash is suitable as a mineral additive in polymer–cement composites. The most interesting result is that the addition of biomass fly ash did not affect the rheological properties of the polymer–cement mortars, but it especially influenced its compressive strength. Most importantly, our findings can help prevent this byproduct from being placed in landfills, prevent the mining of new raw materials, and promote the manufacture of durable building materials.

scholarly journals Analytical Investigation on the Effect of Test Setup on Bond Strength

CivilEng ◽  
2021 ◽  
Vol 2 (1) ◽  
pp. 14-34
Author(s):  
Konstantinos Tsiotsias ◽  
Stavroula J. Pantazopoulou
Keyword(s):  
Bond Strength ◽  
Pullout Test ◽  
Analytical Investigation ◽  
Strength Increase ◽  
Confining Stress ◽  
Direct Tension ◽  
Bond Slip ◽  
Test Setup ◽  
Long Time

Experimental procedures used for the study of reinforcement to concrete bond have been hampered for a long time by inconsistencies and large differences in the obtained behavior, such as bond strength and mode of failure, depending on the specimen form and setup used in the test. Bond is controlled by the mechanics of the interface between reinforcement and concrete, and is sensitive to the influences of extraneous factors, several of which underlie, but are not accounted for, in conventional pullout test setups. To understand and illustrate the importance of specimen form and testing arrangement, a series of computational simulations are used in the present work on eight distinct variants of conventional bar pullout test setups that are used routinely in experimental literature for the characterization of bond-slip laws. The resulting bond strength increase generated by unaccounted confining stress fields that arise around the bar because of the boundary conditions of the test setup is used to classify the tests with respect to their relevance with the intended use of the results. Of the pullout setups examined, the direct tension pullout test produced the most conservative bond strength results, completely eliminating the contributions from eccentricity and passive confinement.

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.

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