再生骨料及再生混凝土的改性研究

全面综述了再生骨料和再生混凝土改性的试验方法、试验条件和改性效果.     

回收废旧电池外壳聚丙烯的力学和耐热性能研究

社会经济的发展和生活水平的提高使得汽车保有量逐年增加,服役后报废汽车产生的废旧蓄电池也快速上升,报废的蓄电池给环境带来巨大压力.废旧电池外壳是聚丙烯,如何循环利用成为亟待解决问题.采用高抗冲共聚聚丙烯对其进行增韧改性,结果表明:当添加20％共聚聚丙烯后,缺口冲击强度提升39.2％,熔体流动速率降低了48.3％,在150...     

Investigating mechanical properties and durability of concrete containing recycled rubber ash and fibers

This article investigates the suitability of utilizing end of life rubber tyre particles in concrete as fine aggregate. Rubber ash and rubber fibers were used to develop two series of rubber ash concrete (series I) and hybrid concrete (series II) mixes. The natural fine aggregate was replaced by rubber ash (by volume of 5%, 10%, 15% and 20%) in series I; whereas in series II, the amount of rubber ash was kept constant at 10% and rubber fiber was introduced as replacement of fine aggregate (by volume of 5%, 10%, 15%, 20% and 25%). The concrete mixes were evaluated for compressive strength, flexural strength, resistance to impact loading, fatigue loading, water penetration and shrinkage strain was evaluated. It was observed that inclusion of rubber ash resulted in the improvement of impact resistance of concrete. The results also show that up to 10% rubber ash and rubber fibers can be utilized as fine aggregate to develop feasible and durable rubberized concrete pavements, crash barriers and paver blocks.

     

Eco-efficient concretes: the effects of using recycled ceramic material from sanitary installations on the mechanical properties of concrete

The aim of this research was to investigate some of the physical and mechanical properties of concrete mixed under laboratory conditions, where different proportions of coarse aggregate materials were substituted by porcelain from sanitary installations. The results of the tests show that the concrete produced has the same mechanical characteristics as conventional concrete, thus opening a door to selective recycling of sanitary porcelain and its use in the production of concrete.     

Effects of recycled glass substitution on the physical and mechanical properties of clay bricks

In this study, wasted glasses from structural glass walls up to 45 wt.% were added into clay mixtures in brick manufacturing process. Physical and mechanical properties of clay bricks were investigated as functions of the wasted glass content and the firing temperature. The results indicated that with proper amount of wasted glasses and firing temperature, clay bricks with suitable physical and mechanical properties could be obtained. The compressive strength as high as 26–41 MPa and water absorption as low as 2–3% were achieved for bricks containing 15–30 wt.% of glass content and fired at 1100 °C. When the glass waste content was 45 wt.%, apparent porosity and water absorption was rapidly increased.     

Study on mechanical properties and microstructure of recycled fine aggregate concrete modified by Nano-SiO2

Journal of Material Cycles and Waste Management - In this study, the effects of different contents of Nano-SiO2 (NS) on a slump, compressive strength, splitting tensile strength, flexural strength,...     

冷冻胶粉粒度对橡胶胶料力学性能的影响

研究了冷冻胶粉粒度对橡胶胶料力学性能的影响,发现添加冷冻胶粉会使胶料的力学性能下降,胶粉粒度越大,胶料性能下降的程度越严重。同时还发现,薄通处理可以改善胶粉的表面活性,减轻胶粉粒度对胶料性能的影响,改善胶料的力学性能。     

Influence of recycled aggregate quality and proportioning criteria on recycled concrete properties

This paper presents the results of experimental research using concrete produced by substituting part of the natural coarse aggregates with recycled aggregates from concrete demolition. The influence of the quality of the recycled aggregate (amount of declassified and source of aggregate), the percentage of replacement on the targeted quality of the concrete to be produced (strength and workability) has been evaluated. The granular structure of concrete and replacement criteria were analyzed in this study, factors which have not been analyzed in other studies. The following properties of recycled concretes were analyzed: density, absorption, compressive strength, elastic modulus, amount of occluded air, penetration of water under pressure and splitting tensile strength.A simplified test program was designed to control the costs of the testing while still producing sufficient data to develop reliable conclusions in order to make the number of tests viable whilst guaranteeing the reliability of the conclusions.Several factors were analyzed including the type of aggregate, the percentage of replacement, the type of sieve curve, the declassified content, the strength of concrete and workability of concrete and the replacement criteria. The type of aggregate and the percentage of replacement were the only factors that showed a clear influence on most of the properties.Compressive strength is clearly affected by the quality of recycled aggregates. If the water–cement ratio is kept constant and the loss of workability due to the effect of using recycled aggregate is compensated for with additives, the percentage of replacement of the recycled aggregate will not affect the compressive strength.The elastic modulus is affected by the percentage of replacement. If the percentage of replacement does not exceed 50%, the elastic modulus will only change slightly.     

Influence of acetic acid soaking and mechanical grinding treatment on the properties of treated recycled aggregate concrete

Journal of Material Cycles and Waste Management - The utilization of recycled aggregate (RA) extracted from construction and demolition (C&D) waste contributes to reducing the usage of...     

Waste biomass and recycled polypropylene based jute hybrid composites for non-structural applications

Journal of Material Cycles and Waste Management - There is an overwhelming interest in composite materials derived from bio-based waste resources, recycled plastic materials and their combinations....     

Leaching and mechanical behaviour of concrete manufactured with recycled aggregates

The reuse of debris from building demolition is of increasing public interest because it decreases the volume of material to be disposed to landfill. This research is focused on the evaluation of the possibility of reusing recycled aggregate from construction or demolition waste (C&D) as a substitute for natural aggregate in concrete production. In most applications, cement based materials are used for building construction due to their cost effectiveness and performance; however their impact on the surrounding environment should be monitored. The interstitial pore fluid in contact with hydrated cementitious materials is characterized by persistent alkaline pH values buffered by the presence of hydrate calcium silicate, portlandite and alkaline ions. An experimental plan was carried out to investigate concrete structural properties in relation to alkali release in aqueous solution. Results indicate that the presence of recycled aggregate increases the leachability of unreactive ions (Na, K, Cl), while for calcium the substitution resulted in a lower net leaching. In spite of the lower mechanical resistance (40% less), such a waste concrete may be suggested as more environmentally sustainable.     

Evaluation of recycled textile wastes with E-glass fabric in bio-based epoxy matrix composites: investigation of the mechanical properties

Journal of Material Cycles and Waste Management - The goal of this study is to recycle diverse textile wastes and use them as cutting-edge and sustainable raw materials in composite structures. In...     

Investigation of physical and mechanical properties of mortars produced with recycled asphalt waste under the influence of high temperature

Journal of Material Cycles and Waste Management - In recent years, the use of waste products in cement-based building materials has been increasing. In this study, it is aimed to examine the...     

Restoring mechanism of mechanical properties of recycled polyethylene pellet moldings by a repelletizing treatment using a twin-screw extruder

Journal of Material Cycles and Waste Management - To develop material-recycling processes for used plastic products, it is necessary to design new material-recycling techniques to optimize the...     

Recent progress on preparation and properties of nanocomposites from recycled polymers: A review

Currently, the growing consumption of polymer products creates the large quantities of waste materials resulting in public concern in the environment and people life. Nanotechnology is assumed the important technology in the current century. Recently, many researchers have tried to develop this new science for polymer recycling. In this article, the application of different nanofillers in the recycled polymers such as PET, PP, HDPE, PVC, etc. and the attributed composites and blends is studied. The morphological, mechanical, rheological and thermal properties of prepared nanocomposites as well as the future challenges are extensively discussed. The present article determines the current status of nanotechnology in the polymer recycling which guide the future studies in this attractive field.     

Potential resources of post-consumer wood waste in Poland

Journal of Material Cycles and Waste Management - This article presents the results of studies, whose aim was to determine the volume of post-consumer wood waste resources in Poland and propose a...     

Valorization of post-consumer waste plastic in cementitious concrete composites

The sheer amount of disposable bottles being produced nowadays makes it imperative to identify alternative procedures for recycling them since they are non-biodegradable. This paper describes an innovative use of consumed plastic bottle waste as sand-substitution aggregate within composite materials for building application. Particularly, bottles made of polyethylene terephthalate (PET) have been used as partial and complete substitutes for sand in concrete composites. Various volume fractions of sand varying from 2% to 100% were substituted by the same volume of granulated plastic, and various sizes of PET aggregates were used. The bulk density and mechanical characteristics of the composites produced were evaluated. To study the relationship between mechanical properties and composite microstructure, scanning electron microscopy technique was employed. The results presented show that substituting sand at a level below 50% by volume with granulated PET, whose upper granular limit equals 5mm, affects neither the compressive strength nor the flexural strength of composites. This study demonstrates that plastic bottles shredded into small PET particles may be used successfully as sand-substitution aggregates in cementitious concrete composites. These new composites would appear to offer an attractive low-cost material with consistent properties; moreover, they would help in resolving some of the solid waste problems created by plastics production and in saving energy.     

Effect of plasticizer dosage on properties of multiple recycled aggregate concrete

Journal of Material Cycles and Waste Management - Recently, studies on multiple recycling of concrete have been attracting attention. In general, multiple recycling increases adhered mortar content...     

Development of composite materials by mechanochemical treatment of post-consumer plastic waste

Improvement of mechanical properties of recycled mixed plastic waste is one of the fundamental goals in any recycling process. However, polymer immiscibility makes the development of any effective reprocessing method difficult. In this work, a polymer milling process with liquid CO2 was applied to polymeric mixed waste, obtaining a powder material which was successfully utilized as a matrix for a new composite material. Developed materials have interesting mechanical properties and material performance can easily be improved. Investigations on selected mixtures of PP and PE clearly showed evidence of chemical compatibilization.     

Catalytic effect of natural clays on properties and chemical structure of recycled polyethylene

Journal of Material Cycles and Waste Management - Montmorillonite clays such as bentonites are often studied and used as reinforcement to thermoplastics, since it can generate nanostructures,...