scholarly journals Effect of experimental wet and dry cycles on bamboo fibre reinforced acrylic polymer modified cement composites

2020 ◽  
Vol 29 (1) ◽  
pp. 86-93
Author(s):  
Banjo A. Akinyemi ◽  
Temidayo E. Omoniyi
Keyword(s):  
Dimensional Stability ◽  
Harmful Effect ◽  
Fibre Surface ◽  
Modulus Of Rupture ◽  
Cement Matrix ◽  
Cement Composites ◽  
Acrylic Polymer ◽  
Vegetable Fibre ◽  
Fibre Cement ◽  
Wet And Dry Cycles

AbstractThis study experimentally evaluated the effect of accelerated wet/dry cycles on the dimensional stability and some selected mechanical properties of polymer modified vegetable fibre cement composites. The bamboo fibres were pre-treated with 10% conc. of sodium hydroxide and varied from 0 – 2.0% while acrylic polymer admixture of 10% w/w of cement was added to improve the properties. The modified fibre-cement composites were subjected to 50 cycles of wet/dry processes to simulate natural weathering process of the environment. The samples were subjected to water absorption, thickness swelling, modulus of rupture (MOR) and modulus of elasticity (MOE) after 28 days of curing and aging cycles respectively using 5 replicates. One way ANOVA at p<0.05 was used to analyse the results. Scanning electron microscope (SEM) and Fourier Transformer Infrared Spectroscopy (FTIR) analyses were conducted on the samples. The results showed improvement of 33.3, 64, 71 and 57% in MOR and 135, 85, 101 and 188% in MOE for samples with 0.5, 1, 1.5 and 2% fibre inclusion after ageing tests. Significantly improved dimensional stability values were observed in this study in comparison with data from similar ageing tests conducted on unmodified vegetable fibre-cement matrix. SEM micrographs showed marginal increase in the size of the pores before and after ageing tests. FTIR analysis indicated increase in intensities during the ageing tests especially for spectra bands located at 3384 – 3520cm−1 which are denoted for OH vibration stretching as well as 1676, 1726 and 1794 cm−1 which depict the presence of carbonyl groups because of absorption of polymers to the fibre surface during the ageing cycles. The study has shown thatwet/dry ageing cycles showed less harmful effect on vegetable fibre cement composites provided the cement matrix is modified with polymer admixtures.

scholarly journals Nanocelluloses: Natural-Based Materials for Fiber-Reinforced Cement Composites. A Critical Review

Polymers ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 518 ◽  
Author(s):  
Ana Balea ◽  
Elena Fuente ◽  
Angeles Blanco ◽  
Carlos Negro
Keyword(s):  
Raw Material ◽  
Modulus Of Rupture ◽  
Cement Matrix ◽  
Future Research ◽  
Cementitious Composites ◽  
Natural Material ◽  
Cement Composites ◽  
Fiber Reinforced ◽  
Industrial Sectors ◽  
Reinforced Cement

Nanocelluloses (NCs) are bio-based nano-structurated products that open up new solutions for natural material sciences. Although a high number of papers have described their production, properties, and potential applications in multiple industrial sectors, no review to date has focused on their possible use in cementitious composites, which is the aim of this review. It describes how they could be applied in the manufacturing process as a raw material or an additive. NCs improve mechanical properties (internal bonding strength, modulus of elasticity (MOE), and modulus of rupture (MOR)), alter the rheology of the cement paste, and affect the physical properties of cements/cementitious composites. Additionally, the interactions between NCs and the other components of the fiber cement matrix are analyzed. The final result depends on many factors, such as the NC type, the dosage addition mode, the dispersion, the matrix type, and the curing process. However, all of these factors have not been studied in full so far. This review has also identified a number of unexplored areas of great potential for future research in relation to NC applications for fiber-reinforced cement composites, which will include their use as a surface treatment agent, an anionic flocculant, or an additive for wastewater treatment. Although NCs remain expensive, the market perspective is very promising.

Processing Changes of Cement Based Composites Reinforced with Silane and Isocyanate Eucalyptus Modified Fibres

2012 ◽  
Vol 517 ◽  
pp. 437-449
Author(s):  
Gustavo Henrique Denzin Tonoli ◽  
M.N. Belgacem ◽  
G. Siqueira ◽  
J. Bras ◽  
Lourival M. Mendes ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Water Retention ◽  
Cement Matrix ◽  
Cement Composites ◽  
Cellulose Fibres ◽  
Dimensional Changes ◽  
Cellulose Pulp ◽  
Pulp Fibres ◽  
Fibre Cement ◽  
Dimensional Instability

Fibre-cement products had been widely used in the world due to their versatility as corrugated and flat roofing materials, cladding panels and water containers presented in large number of building and agriculture applications. The main reason for incorporating fibres into the cement matrix is to improve the toughness, tensile strength, and the cracking deformation characteristics of the resultant composite. One of the drawbacks associated with cellulose fibres in cement application is their dimensional instability in the presence of changing relative humidity. The objective of the present work is to evaluate the effect of surface treatment of eucalyptus cellulose pulp fibres on the processing and dimensional changes of fibre-cement composites. Surface modification of the cellulose pulps was performed with methacryloxypropyltri-methoxysilane (MPTS), aminopropyltri-ethoxysilane (APTS) and n-octadecyl isocyanate, an aliphatic isocyanate (AI), in an attempt to improve their dimensional instability into fibre-cement composites. X-ray photoelectron spectroscopy (XPS) showed the chemical changes occurred at the surface, and contact angle measurements showed the changes in the surface energy. MPTS-and AI-treated fibres presented lower hydrophilic character than untreated fibres, which led to lower water retention values (WRV). APTS increased the water retention value of the pulp and improved the capacity of hydrogen bonding of the fibres. MPTS-and AI-treated fibres led to low final water/cement ratios and reduced volume changes after pressing. MPTS-treated fibres decreased the water and dimensional instability of the fibre-cement composites, while the contrary occurred with APTS-modified and AI-modified fibres.These results are promising and contribute for new strategy to improve processing and stability of natural fibres-reinforced cement products.

Adjusting curing parameters for innovative and durable vegetable fibre-cement composites

2019 ◽  
Vol 103 ◽  
pp. 121-133 ◽  
Author(s):  
Gloria Esther Urrea-Ceferino ◽  
Daman K. Panesar ◽  
Holmer Savastano
Keyword(s):  
Cement Composites ◽  
Vegetable Fibre ◽  
Fibre Cement

Non-Destructive and Destructive Monitoring Methods of Fibre Concrete Homogeneity

2017 ◽  
Vol 259 ◽  
pp. 9-14 ◽  
Author(s):  
René Čechmánek ◽  
Martina Drdlová ◽  
Martin Bohac
Keyword(s):  
Cement Matrix ◽  
Fibre Reinforcement ◽  
Cement Composites ◽  
Monitoring Methods ◽  
Destructive Testing ◽  
Thin Sections ◽  
Wide Range ◽  
Fibre Cement ◽  
Non Destructive ◽  
Destructive Methods

Design, preparation and testing of fibre-cement composites are a task of wide range of research workplaces and universities in our country and abroad. However, a question on homogeneity of all cement matrix components and mainly optimal dispersion of fibre reinforcement in a mixture has not been yet solved sufficiently. Within testing of properties of such designed composites there is usually a realized fact, that variability of these properties is distinctive mainly for the reason of uneven dispersion of commonly used fibres in a whole matrix volume. Elimination of this phenomenon could be achieved by means of a design of the optimal homogenization process of dry mixture components with fibre reinforcement. The aim of research works was to find suitable homogenization techniques, design of mixing process and optimal dosing of individual components. By means of these actions it is possible to achieve the best dispersion of selected fibre types, both metal and non-metal, in fine-grained cementitious matrixes, which is subsequently verified in hardened composites at first by non-destructive and then by destructive methods. Four different fibre-cement mixtures were chosen as representatives for commonly used reinforcement in fibre-cement composites and test specimens with a thickness of 40 mm were prepared using processes suitable for the specific fibre reinforcement. At the first stage non-destructive testing by means of ultrasound waves was carried out at first on a compact test slab with dimensions 500 x 500 x 40 mm and subsequently on individual test specimens with dimensions 250 x 40 x 40 mm, cut from the test slab according to a designed pattern. At the second stage destructive testing of test specimens was performed, mainly evaluation of flexural strength with 4-point bending and subsequently preparation of thin sections from the failure area for observation by means of polarizing microscopy. A purpose of all these research works is finding of correlation between testing by means of destructive and non-destructive methods.

Isocyanate-treated cellulose pulp and its effect on the alkali resistance and performance of fiber cement composites

Holzforschung ◽  
2013 ◽  
Vol 67 (8) ◽  
pp. 853-861 ◽  
Author(s):  
Gustavo Henrique Denzin Tonoli ◽  
Rafael F. Mendes ◽  
Gilberto Siqueira ◽  
Julien Bras ◽  
Mohamed N. Belgacem ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Natural Fibers ◽  
Accelerated Aging ◽  
Cellulose Fiber ◽  
Modulus Of Rupture ◽  
Alkali Resistance ◽  
Cement Matrix ◽  
Cement Composites ◽  
Cellulose Pulp ◽  
The Impact

Abstract The impact of grafted surface of cellulose fibers on the mechanical and physical properties of fiber-cement composites (FCC) has been investigated. The grafting was performed with n-octadecyl isocyanate [i.e., with an aliphatic isocyanate (AI)], with the intention to protect the cellulose fiber from alkali degradation in the cement matrix. The chemical changes, observed by contact angle measurements and X-ray photoelectron spectroscopy, showed a higher hydrophobic character of AI-treated fibers. The strength of FCC was tested during 28 days of curing treatment. The extracted AI-treated fibers contributed to higher specific energy and final specific deflection after accelerated aging cycles in comparison with the reference composites reinforced with untreated fibers. The higher values of limit of proportionality and modulus of elasticity for composites with AI-treated fibers are an evidence of the densification of the fiber-matrix transition zone. The modulus of rupture values were higher for composites with AI-treated and Soxhlet-extracted fibers after 200 soak and dry aging cycles. In comparison with the reference, AI-treated fibers decreased the water absorption and the apparent porosity of the FCC. The modification of fibers could be a new strategy to improve the performance and stability of cement products reinforced with natural fibers.

Bio-Corrosion of Fibrous Cement Boards and Cement Composites

2015 ◽  
Vol 227 ◽  
pp. 207-210
Author(s):  
Vlasta Ondrejka Harbuľáková ◽  
Adriana Eštoková ◽  
Alena Luptáková ◽  
Martina Kovalčíková
Keyword(s):  
Slovak Republic ◽  
Xrd Analysis ◽  
Cement Matrix ◽  
Cement Composites ◽  
Liquid Media ◽  
Abiotic Environment ◽  
X Ray ◽  
Fibre Cement ◽  
The Comparative Study ◽  
Surface Changes

The paper deals with the comparative study of bio-corrosion of fibrous cement boards and Portland cement composites. Fibre-cement flat boards are widely used materials in the Slovak Republic for exterior and interior cladding, as fibre-cement slates for roofing and cladding and as fibre-cement corrugated sheets for roofing and cladding. Bio-corrosion of studied materials has been simulated in laboratory conditions during 80 days. Effect of sulphur-oxidizing bacteria Acidithiobacillusthiooxidans on the specimens was investigated. The bio-deterioration processes have been manifested by leaching of main cement components as well as by surface changes. The calcium and silicon contents in leachates were evaluated during the experiments using X – ray fluorescence method (XRF). Concluding the results of the concrete’s biodeteriogens influence on the analyzed samples (fiber boards and cement composites) more extensive leaching of calcium ions from the cement matrix was confirmed as assumed by bacteria influence when compared to the abiotic environment. Mixture of white compounds on the samples surface was identified by SEM microscopy and XRD analysis as sulphate products (ettringite, thaumasite, gypsum). Shift of pH of liquid media to alkaline region up to 7.2 due to alkaline products leaching were noticed for all studied samples.

The Development of Cement Composites Reinforced Coconut Fiber with Fly Ash Addition: Mechanical Properties and Fracture Behavior

2013 ◽  
Vol 795 ◽  
pp. 128-132
Author(s):  
Nur Izzati Muhd Nadzri ◽  
Shamsul Baharin Jamaludin ◽  
Mohd Noor Mazlee
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Fly Ash ◽  
Fracture Behavior ◽  
Weight Ratio ◽  
Research Paper ◽  
Modulus Of Rupture ◽  
Cement Matrix ◽  
Cement Composites ◽  
Coconut Fiber

This research paper presents a study on the development of cement composites reinforced coconut fiber with fly ash addition. Various content of coconut fiber (3 wt. %, 6 wt. %, 9 wt. %, 12 wt. % and 15 wt. %) was added to the cement composites composition as reinforcement. Additions of 20 wt. % fly ash and 80 wt. % of sand were used as a mixture of cement matrix. Water to cement weight ratio ranging from 0.55 to 0.70 was used in the cement composites to maintain workability. The cement composites were then cured for 7, 14 and 28 days. The result is presented in terms of compressive strength, modulus of rupture and fracture behavior.

Weathering of vegetable fibre-clinker free cement composites

10.1617/13671 ◽  
2001 ◽  
Vol 35 (245) ◽  
pp. 64-68
Author(s):  
H. Savastano, Jr.
Keyword(s):  
Cement Composites ◽  
Vegetable Fibre

Selected Properties of Parallel Strand Lumber Made from Southern Pine and Yellow-Poplar

Holzforschung ◽  
2003 ◽  
Vol 57 (2) ◽  
pp. 207-212 ◽  
Author(s):  
Y. Liu ◽  
A.W.C. Lee
Keyword(s):  
Compressive Strength ◽  
Shear Strength ◽  
Specific Gravity ◽  
Moisture Content ◽  
Dimensional Stability ◽  
Modulus Of Rupture ◽  
Southern Pine ◽  
Yellow Poplar ◽  
Average Modulus ◽  
Parallel Strand Lumber

Summary This study was conducted to explore basic physical and mechanical properties of parallel strand lumber (PSL) made exclusively from southern pine and yellow-poplar, respectively, and to examine their relationships using statistical analysis. Small specimens were prepared from commercial southern pine PSL and yellow-poplar PSL billets and tested for specific gravity, moisture content, dimensional stability, bending properties, shear strength and compressive strength. Results indicate average specific gravity of southern pine PSL is higher than that of yellow-poplar PSL, while their average moisture content and dimensional stability are very similar. Southern pine PSL has higher average modulus of elasticity but lower average modulus of rupture than yellow-poplar PSL. While average longitudinal shear strength does not exhibit differences between southern pine PSL and yellow-poplar PSL, average compressive strength of southern pine PSL is higher than that of yellow-poplar PSL. There are positive correlations among modulus of elasticity, modulus of rupture and specific gravity. PSL improves some properties of solid wood from which PSL is made.

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