scholarly journals The Impact Resistance and Deformation Performance of Novel Pre-Packed Aggregate Concrete Reinforced with Waste Polypropylene Fibres

Crystals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 788 ◽  
Author(s):  
Fahed Alrshoudi ◽  
Hossein Mohammadhosseini ◽  
Rayed Alyousef ◽  
Mahmood Md. Tahir ◽  
Hisham Alabduljabbar ◽  
...  

Pre-packed aggregate fibre-reinforced concrete (PAFRC) is an innovative type of concrete composite using a mixture of coarse aggregates and fibres which are pre-mixed and pre-placed in the formwork. A flowable grout is then injected into the cavities between the aggregate mass. This study develops the concept of a new PAFRC, which is reinforced with polypropylene (PP) waste carpet fibres, investigating its mechanical properties and impact resistance under drop weight impact load. Palm oil fuel ash (POFA) is used as a partial cement replacement, with a replacement level of 20%. The compressive strength, impact resistance, energy absorption, long-term drying shrinkage, and microstructural analysis of PAFRC are explored. Two methods of grout injection are used—namely, gravity and pumping methods. For each method, six PAFRC batches containing 0–1.25% fibres (with a length of 30 mm) were cast. The findings of the study reveal that, by adding waste PP fibre, the compressive strength of PAFRC specimens decreased. However, with longer curing periods, the compressive strength enhanced due to the pozzolanic activity of POFA. The combination of fibres and POFA in PAFRC mixtures leads to the higher impact strength energy absorption and improved ductility of the concrete. Furthermore, drying shrinkage was reduced by about 28.6% for the pumping method PAFRC mix containing 0.75% fibres. Due to the unique production method of PAFRC and high impact resistance and energy absorption, it can be used in many pioneering applications.

2021 ◽  
Vol 13 (4) ◽  
pp. 2073 ◽  
Author(s):  
Hossein Mohammadhosseini ◽  
Rayed Alyousef ◽  
Mahmood Md. Tahir

Recycling of waste plastics is an essential phase towards cleaner production and circular economy. Plastics in different forms, which are non-biodegradable polymers, have become an indispensable ingredient of human life. The rapid growth of the world population has led to increased demand for commodity plastics such as food packaging. Therefore, to avert environment pollution with plastic wastes, sufficient management to recycle this waste is vital. In this study, experimental investigations and statistical analysis were conducted to assess the feasibility of polypropylene type of waste plastic food tray (WPFT) as fibrous materials on the mechanical and impact resistance of concrete composites. The WPFT fibres with a length of 20 mm were used at dosages of 0–1% in two groups of concrete with 100% ordinary Portland cement (OPC) and 30% palm oil fuel ash (POFA) as partial cement replacement. The results revealed that WPFT fibres had an adverse effect on the workability and compressive strength of concrete mixes. Despite a slight reduction in compressive strength of concrete mixtures, tensile and flexural strengths significantly enhanced up to 25% with the addition of WPFT fibres. The impact resistance and energy absorption values of concrete specimens reinforced with 1% WPFT fibres were found to be about 7.5 times higher than those of plain concrete mix. The utilisation of waste plastic food trays in the production of concrete makes it low-cost and aids in decreasing waste discarding harms. The development of new construction materials using WPFT is significant to the environment and construction industry.


Polymers ◽  
2021 ◽  
Vol 13 (24) ◽  
pp. 4416
Author(s):  
Yanyan Lin ◽  
Huaguan Li ◽  
Zhongwei Zhang ◽  
Jie Tao

The weak interface performance between metal and composite (IPMC) makes the composite materials susceptible to impact load. Aluminum/glass fiber/polypropylene (Al/Gf/PP) laminates were manufactured with the aluminum alloy sheets modified by nitrogen plasma surface treatment and the phosphoric acid anodizing method, respectively. FEM models of Al/Gf/PP laminates under low-velocity impact were established in ABAQUS/Explicit based on the generated data including the model I and II interlaminar fracture toughness. Low-velocity impact tests were performed to investigate the impact resistance of Al/Gf/PP laminates including load traces, failure mechanism, and energy absorption. The results showed that delamination was the main failure mode of two kinds of laminates under the impact energy of 20 J and 30 J. When the impact energy was between 40 J and 50 J, there were metal cracks on the rear surface of the plasma pretreated specimens, which possessed higher energy absorption and impact resistance, although the integrity of the laminates could not be preserved. Since the residual compressive stress was generated during the cooling process, the laminates were more susceptible to stretching rather than delamination. For impact energy (60 J) causing the through-the-thickness crack of two kinds of laminates, plasma pretreated specimens exhibited higher SEA values close to 9 Jm2/kg due to better IPMC. Combined with the FEM simulation results, the interface played a role in stress transmission and specimens with better IPMC enabled the laminates to absorb more energy.


2020 ◽  
Vol 14 (2) ◽  
pp. 6734-6742
Author(s):  
A. Syamsir ◽  
S. M. Mubin ◽  
N. M. Nor ◽  
V. Anggraini ◽  
S. Nagappan ◽  
...  

This study investigated the combine effect of 0.2 % drink cans and steel fibers with volume fractions of 0%, 0.5%, 1%, 1.5%, 2%, 2.5% and 3% to the mechanical properties and impact resistance of concrete. Hooked-end steel fiber with 30 mm and 0.75 mm length and diameter, respectively was selected for this study.  The drinks cans fiber were twisted manually in order to increase friction between fiber and concrete. The results of the experiment showed that the combination of steel fibers and drink cans fibers improved the strength performance of concrete, especially the compressive strength, flexural strength and indirect tensile strength. The results of the experiment showed that the combination of steel fibers and drink cans fibers improved the compressive strength, flexural strength and indirect tensile strength by 2.3, 7, and 2 times as compare to batch 1, respectively. Moreover, the impact resistance of fiber reinforced concrete has increase by 7 times as compared to non-fiber concretes. Moreover, the impact resistance of fiber reinforced concrete consistently gave better results as compared to non-fiber concretes. The fiber reinforced concrete turned more ductile as the dosage of fibers was increased and ductility started to decrease slightly after optimum fiber dosage was reached. It was found that concrete with combination of 2% steel and 0.2% drink cans fibers showed the highest compressive, split tensile, flexural as well as impact strength.    


2017 ◽  
Vol 865 ◽  
pp. 612-618 ◽  
Author(s):  
M. Malawat ◽  
Jos Istiyanto ◽  
D.A. Sumarsono

Crush initiators are the weakest points to reduce initial peak load force with significant energy absorption ability. The objective of this paper is to study the effects of square tube thickness and crush initiators position for impact energy absorber (IEA) performance on thin-walled square tubes. Two square tubes having thickness about 0.6 mm (specimen code A) and 1 mm (specimen Code C) were tested under dynamic load. The crushing initiator is designed around the shape of the tube wall and has eight holes with a fixed diameter of 6.5 mm. In the experiment, the crushing initiator was determined at 5 different locations on the specimen wall. These locations are 10 mm, 20 mm. 30 mm, 40 mm, and 50 mm measured from the initial collision position of the specimen tested. The impact load mass was about 80 kg and had a drop height of about 1.5 m. Using the simulation program of the LabVIEW Professional Development System 2011 and National Instrument (NI) 9234 software equipped with data acquisition hardware NI cDAQ-9174 the signal from the load cell was sent to a computer. By controlling the thickness of the thin-walled square tube, the peak loading force can be decreased by approximately 56.75% and energy absorption ability of IEA can be increased approximately to 11.83%. By using different thin-walled square tube can produce different best crush initiators position with the lowest peak load force.


2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Srinivasan Karunanithi

The study was focused on slag based geopolymer concrete with the addition of steel fibre. The slag based geopolymer concrete was under shear load and sudden impact load to determine its response. The punching shear represents the load dissipation of the material and the energy absorption capacity of the geopolymer concrete to impact load. The various percentage of steel fibre in the slag based geopolymer concrete was 0.5%, 1.0%, and 1.5%. Overall the dosage 0.5% of steel fibre reinforced slag based geopolymer shows better results with a punching shear of 224 kN and 1.0% of steel fibre incorporated geopolymer concrete had the better energy absorption capacity with 3774.40 N·m for first crack toughness and 4123.88 N·m for ultimate failure toughness.


BioResources ◽  
2021 ◽  
Vol 16 (2) ◽  
pp. 2249-2263
Author(s):  
María Alejandra Ramírez-Ramírez ◽  
Artemio Carrillo-Parra ◽  
Faustino Ruíz-Aquino ◽  
Luis Fernando Pintor-Ibarra ◽  
Nicolás González-Ortega ◽  
...  

This research characterized briquettes made with Pinus spp. sawdust without the use of additives. For this purpose, 19 samples of sawdust from different wood industries located in five states of the Mexican Republic were used. The densification process was carried out in a vertical hydraulic piston laboratory briquette machine. The briquettes were made with 40 g of sawdust, at 50 °C, 20 kPa and pressing for 5 min. The results obtained varied as follows: moisture content (4.1% to 7.2%), density (813.9 to 1,014.4 kg/m3), volumetric expansion (7.4% to 37.3%), compressive strength (4.9 to 40.8 N/mm), impact resistance index (46.7% to 200%), ash (0.1% to 1.1%), volatile matter (82.9% to 90.7%), fixed carbon (8.9% to 16.4%), and calorific value (20.5 to 22.8 MJ/kg). The density of the briquettes was within the “acceptable” classification (800 to 1,200 kg/m3). It was observed that, the higher the density, the lower the volumetric expansion, the higher the compressive strength, and the higher the impact resistance index. According to the ash content, the briquettes could achieve international quality. Due to high volatile matter values, rapid combustion of the briquettes with little generation of toxic smoke would be expected. Fixed carbon and calorific value results were acceptable.


Materials ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 5847
Author(s):  
Xiaohao Li ◽  
Junqi Pan ◽  
Xingchen Zhou

In order to meet the increasing application requirements with regards to structural impact resistance in industries such as mining, construction, aerospace engineering, and disaster relief and mitigation, this paper designs a variant truss beam structure with a large shrinkage ratio and high impact resistance. Based on the principle of the curved trajectory of scissor mechanisms, this paper conducts a finite element simulation analysis of the impact load on the truss beam structure, a theoretical analysis of the impact response and a relevant prototype bench-top experiment, completing a full study on the impact resistance mechanism of the designed variant truss beam structure under the impact load. In the paper, the buffer effect of the external load impact on the variant truss beam structure is analyzed from the perspective of the energy change of elastic–plastic deformation. This paper proposes an optimization strategy for the variant truss beam structure with the energy absorption rate as the optimization index through extensive analysis of the parameter response surfaces. The strategy integrates analyses on the response characteristic analysis of various configuration materials to obtain an optimal combination of component parameters that ensures that the strength of the truss beam structure meets set requirements. The strategy provides a feasible method with which to verify the effectiveness and impact resistance of a variant truss structure design.


Author(s):  
Meivazhisalai Parasuraman Salaimanimagudam ◽  
Covaty Ravi Suribabu ◽  
Gunasekaran Murali ◽  
Sallal R. Abid

Reducing the weight of concrete beams is a primary (beyond strength and durability) concern of engineers. Therefore, this research was directed to investigate the impact response of hammerhead pier concrete beams designed with density-based method topology optimization. The finite element topology optimization was conducted using Autodesk fusion 360 considering three different mesh sizes of 7 mm, 10 mm, and adaptive meshing. Three optimized hammerhead beam configurations; HB1, HB2, and HB3, respectively, with volume reductions greater than 50 %. In the experimental part of this research, nine beams were cast with identical size and configuration to the optimized beams. Three beams, identical to the optimized beams, were tested under static bending for verification purposes. In comparison, six more beams, as in the preceding three beams but without and with hooked end steel fibers, were tested under repeated impact load. The test results revealed that the highest flexural capacity and impact resistance at crack initiation and failure were recorded for the adaptive mesh beams (HB3 and HB3SF). The failure impact energy and ductility ratio of the beam HB3SF was higher than the beams HB1SF and HB2SF by more than 270 %. The results showed that the inclusion of steel fiber duplicated the optimized beam’s impact strength and ductility several times. The failure impact resistance of fibrous beams was higher than their corresponding plain beams by approximately 2300 to4460 %, while their impact ductility ratios were higher by 6.0 to 18.1 times.


2020 ◽  
Vol 54 (28) ◽  
pp. 4387-4395
Author(s):  
Sanchi Arora ◽  
Abhijit Majumdar ◽  
Bhupendra Singh Butola

The beneficial effect of STF impregnation in enhancing the impact resistance of high-performance fabrics has been extensively reported in the literature. However, this research work reports that fabric structure has a decisive role in moderating the effectiveness of STF impregnation in terms of impact energy absorption. Plain woven fabrics having sett varying from 25 × 25 inch−1 to 55 × 55 inch−1 were impregnated with STF at two different padding pressures to obtain different add-ons. The impact energy absorption by STF impregnated loosely woven fabrics was found to be higher than that of their neat counterparts for both levels of add-on, while opposite trend was observed in case of tightly woven fabrics. Further, comparison of tightly woven plain, 2/2 twill, 3/1 twill and 2 × 2 matt fabrics revealed beneficial effect of STF impregnation, except for the plain woven fabric, establishing that there exists a fabric structure-STF impregnation interplay that tunes the impact resistance of woven fabrics.


2020 ◽  
Vol 991 ◽  
pp. 62-69
Author(s):  
Sallehan Ismail ◽  
Mohamad Asri Abd Hamid ◽  
Zaiton Yaacob

This study aims to investigate the dynamic behavior of recycled mortar under impact loading using a split Hopkinson pressure bar (SHPB). Several mortar mixtures were produced by adding various fine recycled aggregates (FRA) to the mixture in replacement percentages of 0%, 25%, 50%, 75%, and 100% of the natural fine aggregate (NFA). The effects of strain rate on compressive strength and specific energy absorption were obtained. Results show that the dynamic compressive strength and specific energy absorption of recycled mortar are highly strain rate dependent; specifically, they increase nearly linearly with the increase in peak strain rate. However, the compressive strength and specific energy absorption of recycled mortar are generally lower than those of NFA mortar (reference samples) under similar high strain rates. The findings of this research can help researchers and construction practitioners to ascertain the appropriate mix design procedure to optimize the impact strength properties of recycled mortar for protective structural application.


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