scholarly journals Unconfined Compressive Properties of Composite Sand Stabilized with Organic Polymers and Natural Fibers

Polymers ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 1576 ◽  
Author(s):  
Yuxia Bai ◽  
Jin Liu ◽  
Zezhuo Song ◽  
Zhihao Chen ◽  
Canhui Jiang ◽  
...  

As renewable and environment-friendly materials, coir and sisal natural fibers can be used in soil reinforcement with minimum cost and other benefits. In this study, we focused on their improvements of unconfined compressive properties of polymer treated sand. In total, 36 groups of unconfined compressive strength tests, combined with X-ray diffraction and scanning electron microscope investigations were performed. We had studied the effects of polymer and fiber contents, and fiber types on the reinforcement effectiveness. The results showed that both coir and sisal fiber can improve the mechanical properties and microstructure of treated sand. In terms of strength properties, sisal fiber inclusion was better than coir fiber, while both have a similar reinforcement benefit on soil ductile behaviors. The strength and compressive energy increased with an increment in polymer and fiber content. The reinforced sand can have up to 1 MPa compressive strength and 140 kPa compressive energy for coir fiber inclusion, while 1.2 MPa and 170 kPa, respectively, for sisal fiber. The axial stress-strain characteristics and failure patterns were also improved, and the brittle index decreased toward zero, which suggests an increasing ductile. The polymer membrane enwrapping and bonding sand grains, and the network structure built by fiber crossing and overlapping among sand grains, as well as the interfacial attachment conferred by polymer between sand grains and fiber, all contributed to the reinforcement of treated sand.

Materials ◽  
2020 ◽  
Vol 13 (14) ◽  
pp. 3194 ◽  
Author(s):  
Zuqian Jiang ◽  
Liwen Zhang ◽  
Tao Geng ◽  
Yushan Lai ◽  
Weile Zheng ◽  
...  

Coir fiber (CF), an eco-friendly and renewable natural fiber, was introduced into magnesium phosphate cement (MPC) mortar to improve its crack resistance. A total of 21 specimens were employed to investigate the failure pattern, compressive strength, stress–strain curve, and energy absorption of MPC with varying CF lengths (0, 5, 10, 15, 20, 25, and 30 mm) after a curing period of 28 days through a static compressive test. The results demonstrated that compressive strength, elastic modulus, and secant modulus decreased with the increase in CF length. However, energy absorption presented a convex curve, which increased to the maximum value (77.0% relative to the value of the specimen without CF) with a CF length of 20 mm and then declined. A series of modern micro-tests were then carried out to analyze the microstructure and composition of specimens to explain the properties microscopically.


In this paper various mix proportions of Reactive Powder Concretes were formulated using ordinary Portland cement, Fly ash, Micro silica, Silica Fume, Quartz powder etc and these concretes were subjected to strength test. The best mix was selected for further in depth study with fibers like Sisal fiber, Coir fiber, Hair fiber and Polypropylene fiber mixed Reactive Powder Concrete and the various tests have been performed Cube Compressive strength, Cylinder Compressive strength, Flexural strength, Split Tensile strength, Shear test, Water absorption, Sorptivity and Chloride diffusion etc. As a result, fiber incorporated concrete shows increasing Flexural strength, splitting tensile strength, and shear strength up to 30% as compared to control RPC and gives minimal decrease in compressive strength by the addition of fibers. These characteristics make it as a promising material for casting non structural elements such as pressure pipes, flooring tiles, Partition panels, door and window frames. It can also be used as repair materials.


2013 ◽  
Vol 701 ◽  
pp. 291-295
Author(s):  
Norwanis Hasan ◽  
Syed Fuad Saiyid Hashim ◽  
Zulkifli Mohamad Ariff

An innovative technique in producing cement syntactic foam (CSF) was proposed in this investigation. This cellular composite material basically consists of a cement matrix embedded with in-house developed cement hollow spheres (CHS). The produced foams incorporated with CHS having different wall thickness, were characterized for compressive strength and then compared with that of plain cement. It was observed that the CSFs were 37%-55% lighter than the plain cement but possessed compromised compressive strength. The comparative compressive properties of CSFs were also evaluated and reported. It was found that the CSF incorporated with thicker-coated CHS showed higher compressive strength compared to that of incorporated with thinner-coated CHS. The failure patterns within the test samples were also examined to determine the failure mechanism. These observations showed that both CSFs exhibited shearing type failure but exhibit different types of crack fractures due to the difference in CHS wall thickness.


Materials ◽  
2019 ◽  
Vol 12 (11) ◽  
pp. 1797 ◽  
Author(s):  
Meng Chen ◽  
Chenhui Ren ◽  
Yangbo Liu ◽  
Yubo Yang ◽  
Erlei Wang ◽  
...  

This paper presents an experimental study on the dynamic compressive behaviour of polypropylene (PP) fibre reinforced concrete under various strain rates using split Hopkinson pressure bar (SHPB) equipment. The effects of PP fibre content and strain rate on the dynamic compressive stress-strain relationship and failure patterns were estimated. The results indicated that the addition of PP fibre enhanced the dynamic compressive properties of concrete mixtures although it resulted in a significant reduction in workability and a slight decrease in static compressive strength. Considering the workability, static compressive strength and dynamic compressive behaviour, the optimal PP fibre content was found to be 0.9 kg/m3 as the mixture exhibited the highest increase in dynamic compressive strength of 5.6%, 40.3% in fracture energy absorption and 11.1% in total energy absorption; further, it showed the least reduction (only 5.8%) in static compressive strength among all mixtures compared to the reference mixture without fibre. For all mixtures, the dynamic compressive properties, energy absorption capacity, strain at peak stress, ultimate strain and dynamic increase factor (DIF) were significantly influenced by strain rate, i.e., strain rate effect. When the strain rate was relatively low, PP fibres were effective in controlling the cracking, and the dynamic compressive properties of PP fibre reinforced mixtures were improved accordingly.


2017 ◽  
Vol 52 (15) ◽  
pp. 2065-2074 ◽  
Author(s):  
Bo Wang ◽  
Nobuhide Uda ◽  
Kousei Ono ◽  
Hiroto Nagai

In this paper, a combination of experimentation and analysis is used to study the effect of micro in-plane fiber waviness on the compressive properties of unidirectional fabric composites. The experimental part includes a measurement of the micro in-plane fiber waviness in two types of unidirectional fabrics, manufacturing composites with each unidirectional fabric via VaRTM process and tests for establishing the compressive modulus and strengths of the composites. The compressive strengths were confirmed to be affected by the micro in-plane fiber waviness, but the compressive modulus was not. Furthermore, a two-dimensional numerical model is proposed to explain our experimental results. The numerical results indicate that the tensile stress (owing to the micro in-plane fiber waviness) and compressive stress along the weft and warp directions, respectively, of the composite lead to reductions in the compressive strength.


2011 ◽  
Vol 243-249 ◽  
pp. 494-498
Author(s):  
Hui Ming Bao

By means of the tests on the mechanics performance of the reinforcing concrete mixed with sisal fibers or rubber powder of certain content are investigated. The compressive strength, tensile strength and flexural strength, etc. are compared. The test indicates that when the test condition is same, the compressive strength, tensile strength and flexural strength of the sisal fibers concrete are better than those of the rubber powder’s. The sisal fiber concrete is environment friendly than the rubber powder concrete. And it has widely value of spread and utilization.


Author(s):  
Divesh Sharma

In this review article, the usage of bitumen, sisal fiber and the sisal fiber for improving the strength parameters of concrete is discussed in detail. Numerous research studies related to the usage of bitumen, sisal fiber and stone dust are studied in detail to determine the results and outcome out of it. Previous research works showed that all, these materials were enhancing the strength and durability aspects of the concrete and depending upon the research studies certain outcomes has been drawn which are as follows. The studies related to the usage of the bitumen or asphalt in concrete so as to produce bituminous concrete or asphaltic concrete, the previous research works conclude that the maximum strength was attained at 5 percent usage of the bitumen and after further usage the general compressive strength of the concrete starts declining. The previous studies related to the usage of the sisal fiber showed that with the usage of the sisal fiber in the concrete, the strength aspects of concrete were improving and the maximum strength was obtained at 1.5 percent usage of the sisal fiber and after his the strength starts declining. Further the studies related to the usage of the stone dust showed that with the usage of stone dust as partial replacement of the natural fine aggregate the compressive strength of the concrete was improving and it was conclude that with the increase in the percentage of the stone dust, the compressive strength of the concrete was increasing.


2021 ◽  
Vol 32 ◽  
pp. 85-97
Author(s):  
Gunturu Bujjibabu ◽  
Vemulapalli Chittaranjan Das ◽  
Malkapuram Ramakrishna ◽  
Konduru Nagarjuna

Banana/Coir fiber reinforced polypropylene hybrid composites was formulated by using twin screw extruder and injection molding machine. Specimens were prepared untreated and treated B/C Hybrid composites with 4% and 8% of MA-g-PP to increase its compatibility with the polypropylene matrix. Both the without MA-g-PP and with MA-g-PP B/C hybrid composites was utilized and three levels of B/C fiber loadings 15/5, 10/10 and 5/15 % were used during manufacturing of B/C reinforced polypropylene hybrid composites. In this work mechanical performance (tensile, flexural and impact strengths) of untreated and treated (coupling agent) with 4% and 8% of MA-g-PP B/C fibers reinforced polypropylene hybrid composite have been investigated. Treated with MA-g-PP B/C fibers reinforced specimens explored better mechanical properties compared to untreated B/C fibers reinforced polypropylene hybrid composites. Mechanical tests represents that tensile, flexural and impact strength increases with increase in concentration of coupling agent compared to without coupling agent MA-g-PP hybrid composites . B/C fibers reinforced polymer composites exhibited higher tensile, flexural and impact strength at 5% of Banana fiber, 15% of fiber Coir in the presence of 8% of MA-g-PP compared to 4% of MA-g-PP and untreated hybrid composites. The percentage of water absorption in the B/C fibers reinforced polypropylene hybrid composites resisted due to the presence of coupling agent MA-g-PP and thermogravimetry analysis (TGA) also has done.


Author(s):  
Anjaly M.

ABSTRACT Traffic is increasing day by day due to increased vehicle ownership and infrastructure development. As the modern highway transportation has high speed, high traffic density, heavy load and channelized traffic, bituminous concrete is subjected to various types of distress such as rutting, fatigue cracking and raveling. Fatigue cracking occurs because bituminous layers are weak in tension. Therefore reinforcement of the bituminous mixes is one approach to improve tensile strength. Natural fibers can be used for reinforcing as a substitute for synthetic fibers due to their lower cost, ecological recycling and low specific gravity. Among natural fibers growing attention is being paid to coir fiber due to its easy availability, good wearing resistance and more durable property. Also rutting along wheel path causes vehicle hydroplaning during rainy seasons due to loss of skid resistance. As well as water accumulated over the longitudinal depressions damages bond between binder and aggregates. Therefore there is a need for a durable mix which can increase the service life of pavement thus reduces life cycle cost. This study is about use of coir fiber in pavement construction to improve the performance characteristics of the asphalt mixture being used. Stone matrix asphalt mixture is a rut resistant and durable mix which is reinforced with coir fiber and tested for various performance characteristics. Coir fiber is a sustainable material which can be used for rutting resistant mixture.   Keywords: Stone matrix asphalt, Coir fiber, rutting


2021 ◽  
Vol 7 (2) ◽  
pp. 58
Author(s):  
Celal Çakıroğlu ◽  
Gebrail Bekdaş

In the recent years natural fiber reinforced composites are increasingly receiving attention from the researchers and engineers due to their mechanical properties comparable to the conventional synthetic fibers and due to their ease of preparation, low cost and density, eco-friendliness and bio-degradability. Natural fibers such as kenaf or flux are being considered as a viable replacement for glass, aramid or carbon. Extensive experimental studies have been carried out to determine the mechanical behavior of different natural fiber types such as the elastic modulus, tensile strength, flexural strength and the Poisson’s ratio. This paper presents a review of the various experimental studies in the field of fiber reinforced composites while summarizing the research outcome about the elastic properties of the major types of natural fiber reinforced composites. Furthermore, the performance of a kenaf reinforced composite plate is demonstrated using finite element analysis and results are compared to a glass fiber reinforced laminated composite plate.


Sign in / Sign up

Export Citation Format

Share Document