scholarly journals Thermoset Polymer Matrix Composites of Epoxy, Unsaturated Polyester, and Novolac Resin Embedding Construction and Demolition Wastes powder: A Comparative Study

Polymers ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 737
Author(s):  
Costas Bogiatzidis ◽  
Loukas Zoumpoulakis
Keyword(s):  
Thermal Conductivity ◽  
Shear Strength ◽  
Mechanical Performance ◽  
Polymer Matrix Composites ◽  
Unsaturated Polyester ◽  
Construction And Demolition Waste ◽  
Demolition Waste ◽  
X Ray ◽  
Thermal Insulating ◽  
The Matrix

Composite materials that consisted of a polymer resin as matrix (PMCs), filled using construction and demolition (C&D) wastes powder of different grain sizing in micro-scale were manufactured and studied. Three different kinds of resins were used as the matrix for the purposes of this study. More specifically, composites made of epoxy and unsaturated polyester resins purchased from the market and phenolic resin (novolac) laboratory synthesized, were produced. The morphological and elemental analysis of these materials was performed through scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), and X-ray diffraction (XRD). Additionally, mechanical performance and thermal insulating efficiency of these materials were examined through bending and shear strength tests according to the three-point method and via determination of the thermal conductivity coefficient λ. C&D wastes have undergone the appropriate processing in order to prepare filling products of the required granular size in pulverized form. In this research study, construction and demolition waste-based thermosetting polymer composites were produced with flexural strength in the range 20–60 MPa, shear strength in between 1–8 MPa, and thermal conductivity coefficients in the range of 0.27–1.20 W/mK. The developed materials embedded 30–50% w/w C&D wastes, depending on the resin used as the matrix.

scholarly journals Evaluation of Physical Properties of a Metakaolin-Based Alkali-Activated Binder Containing Waste Foam Glass

Materials ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 5458
Author(s):  
Petra Mácová ◽  
Konstantinos Sotiriadis ◽  
Zuzana Slížková ◽  
Petr Šašek ◽  
Michal Řehoř ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Physical Properties ◽  
Foam Glass ◽  
Glass Production ◽  
Alkali Activation ◽  
Activation Process ◽  
X Ray ◽  
Thermal Insulating ◽  
The Matrix ◽  
Alkali Activated

Foam glass production process redounds to large quantities of waste that, if not recycled, are stockpiled in the environment. In this work, increasing amounts of waste foam glass were used to produce metakaolin-based alkali-activated composites. Phase composition and morphology were investigated by means of X-ray powder diffraction, Fourier-transform infrared spectroscopy and scanning electron microscopy. Subsequently, the physical properties of the materials (density, porosity, thermal conductivity and mechanical strength) were determined. The analysis showed that waste foam glass functioned as an aggregate, introducing irregular voids in the matrix. The obtained composites were largely porous (>45%), with a thermal conductivity coefficient similar to that of timber (<0.2 W/m∙K). Optimum compressive strength was achieved for 10% incorporation of the waste by weight in the binder. The resulting mechanical properties suggest the suitability of the produced materials for use in thermal insulating applications where high load-bearing capacities are not required. Mechanical or chemical treatment of the waste is recommended for further exploitation of its potential in participating in the alkali activation process.

scholarly journals Using Green Supplementary Materials to Achieve More Ductile ECC

Materials ◽  
2019 ◽  
Vol 12 (6) ◽  
pp. 858 ◽  
Author(s):  
Yichao Wang ◽  
Zhigang Zhang ◽  
Jiangtao Yu ◽  
Jianzhuang Xiao ◽  
Qingfeng Xu
Keyword(s):  
Fracture Toughness ◽  
Tensile Strain ◽  
Tension Test ◽  
Construction And Demolition Waste ◽  
Demolition Waste ◽  
Strain Capacity ◽  
Fiber Bridging ◽  
Matrix Fracture ◽  
The Matrix ◽  
Tensile Strain Capacity

To improve the greenness and deformability of engineered cementitious composites (ECC), recycled powder (RP) from construction and demolition waste with an average size of 45 μm and crumb rubber (CR) of two particle sizes (40CR and 80CR) were used as supplements in the mix. In the present study, fly ash and silica sand used in ECC were replaced by RP (50% and 100% by weight) and CR (13% and 30% by weight), respectively. The tension test and compression test demonstrated that RP and CR incorporation has a positive effect on the deformability of ECC, especially on the tensile strain capacity. The highest tensile strain capacity was up to 12%, which is almost 3 times that of the average ECC. The fiber bridging capacity obtained from a single crack tension test and the matrix fracture toughness obtained from 3-point bending were used to analyze the influence of RP and CR at the meso-scale. It is indicated that the replacement of sand by CR lowers the matrix fracture toughness without decreasing the fiber bridging capacity. Accordingly, an explanation was achieved for the exceeding deformability of ECC incorporated with RP and CR based on the pseudo-strain hardening (PSH) index.

New Thermal Insulating Material Based on Geocement

2013 ◽  
Vol 838-841 ◽  
pp. 183-187 ◽  
Author(s):  
Vít Petranek ◽  
Sergii Guzii ◽  
Pavel Krivenko ◽  
Konstantinos Sotiriadis ◽  
Anastasiia Kravchenko
Keyword(s):  
Thermal Conductivity ◽  
Heat Flow ◽  
External Heat ◽  
Great Scientist ◽  
Insulating Material ◽  
Average Temperature ◽  
Thermal Insulating ◽  
The Matrix ◽  
Birthday Anniversary ◽  
Alkali Activated

A new thermal insulating material was developed on the basis of a geocement, formulated as Na2OAl2O36SiO220H2O. Ground limestone and aluminosilicate pellets were used as fillers for its production (composition: geocement 64.29 wt. [%]; fillers 35.71 wt. [%]). This material, which is applied having a thickness of 3.0-4.5 mm, swells when it is exposed to an external heat flow of 1273 K average temperature. Swelling is due to the matrix phases and filler dehydration, which include heulandite, ussingite, sodium zeolite and other phases. As a result, a finely porous glassy aluminosilicate frame of jadeite-albite composition is formed, which is characterized by low thermal conductivity (0.09-0.175 Wm-1K-1). The developed material can be used to protect and to insulate wooden, metal and concrete surfaces from an one-sided heat source.The paper is dedicated to the great scientist of the XXI century in the field of alkali-activated cements and materials based on them, Pavlo Kryvenko, in honor of his 75thbirthday anniversary.

scholarly journals Thermal Insulating and Mechanical Properties of Cellulose Nanofibrils Modified Polyurethane Foam Composite as Structural Insulated Material

Forests ◽  
2019 ◽  
Vol 10 (2) ◽  
pp. 200 ◽  
Author(s):  
Weiqi Leng ◽  
Biao Pan
Keyword(s):  
Thermal Conductivity ◽  
Polyurethane Foam ◽  
Bending Strength ◽  
Mechanical Performance ◽  
Cellulose Nanofibrils ◽  
Thermal Insulating ◽  
Foaming Process ◽  
Wood Construction ◽  
Closed Cell ◽  
Foam Composite

Cellulose nanofibrils (CNF) modified polyurethane foam (PUF) has great potential as a structural insulated material in wood construction industry. In this study, PUF modified with spray-dried CNF was fabricated and the physical and mechanical performance were studied. Results showed that CNF had an impact on the foam microstructure by increasing the precursor viscosity and imposing resistant strength upon foaming. In addition, the intrinsic high mechanical strength of CNF imparted an extra resistant force against cells expansion during the foaming process and formed smaller cells which reduced the chance of creating defective cells. The mechanical performance of the foam composite was significantly improved by introducing CNF into the PUF matrix. Compared with the PUF control, the specific bending strength, specific tensile strength, and specific compression strength increased up to three-fold for the CNF modified PUF. The thermal conductivity of PUF composite was mainly influenced by the closed cell size. The introduction of CNF improved thermal insulating performance, with a decreased thermal conductivity from 0.0439 W/mK to 0.02724 W/mK.

scholarly journals Mechanical and Durability Properties of Recycled Aggregate Concrete

2021 ◽  
Vol 26 (4) ◽  
Author(s):  
Carolina Shimomura Nanya ◽  
Fernanda Giannotti da Silva Ferreira ◽  
Valdirene Maria da Silva Capuzzo
Keyword(s):  
Mechanical Performance ◽  
Water Immersion ◽  
Chloride Ion ◽  
Chloride Ions ◽  
Recycled Aggregate Concrete ◽  
Construction And Demolition Waste ◽  
Recycled Aggregate ◽  
Void Content ◽  
Demolition Waste ◽  
Chloride Ion Penetration

ABSTRACT This paper investigates how the use of construction and demolition waste can affect the durability and affect the mechanical performance of concrete. tests such as compressive strength, tensile strength by diametral compression and modulus of elasticity were performed. Regarding durability, tests such as water immersion, void content and specific mass, water absorption by capillarity, electrical resistivity, the penetration depth of chloride ions, accelerated carbonation and a test evaluating the synergic effect of carbon dioxide and chloride ion penetration were performed. The coarse natural aggregate was replaced with coarse recycled aggregate in concrete mixes at the following ratios: 30%, 50%, 70%, and 100%. The results indicate that the parameters of the concrete produced with recycled aggregate, especially up to 50% replacement level, meet the concrete quality requirements, regarding the mechanical properties and durability.

scholarly journals Acid Resistance of Lightweight Brick Powder Based Alkali Activated Material from Construction and Demolition Wastes

2018 ◽  
Author(s):  
Kai Tai Wan ◽  
Amende Sivanathan ◽  
Gediminas Kastiukas ◽  
Xiangming Zhou
Keyword(s):  
Acid Resistance ◽  
Strength Loss ◽  
Construction And Demolition Waste ◽  
Demolition Waste ◽  
Construction And Demolition Wastes ◽  
Brick Powder ◽  
Structural Applications ◽  
The Matrix ◽  
Similar Density ◽  
Alkali Activated

The annual construction and demolition waste (CDW) generated from EU construction sector was 850 million tons, which represented 31% of the total waste generation and about 28% of CDW was ceramics (bricks and tiles). In this study, the feasibility of using CDW brick powder as the precursor of alkali activated mortar (AAM) and extruded polystyrene (XPS) as the lightweight aggregates to form lightweight brick powder AAM (LW-BP-AAM) for non-structural applications was investigated. The thermal conductivity of LP-BPAAM was 0.112 W/m&middot;K with density of about 1,135 kg/m3 which was lower than the counterparts with similar density in literature. The acid resistance of LW-BP-AAM is comparable to conventional fly ash based AAM and superior than ordinary Portland cement. From the scanning electron microscopy with energy dispersive X-ray spectroscopy, there was no severe damage on the surface of LW-BP-AAM but aluminate was removed from the matrix which was further verified in Fourier transform infrared spectroscopy. The mass and strength loss of LP-BP-AAM was 1.5% and 33%, respectively. Although the compressive strength of the LP-BP-AAM was low (about 1.8 MPa), it can be improved by optimising the particle size of the XPS aggregates.

scholarly journals Concrete-Based and Mixed Waste Aggregates in Rendering Mortars

2020 ◽  
Author(s):  
Cinthia Maia Pederneiras
Keyword(s):  
Mechanical Performance ◽  
Ceramic Materials ◽  
Cementitious Materials ◽  
Recycled Concrete ◽  
Construction And Demolition Waste ◽  
Recycled Aggregates ◽  
Concrete Aggregate ◽  
Demolition Waste ◽  
Recycled Concrete Aggregates ◽  
Mixed Recycled Aggregates

The construction industry is considered the biggest waste producer in Europe. In order to encourage recycling, European Parliament decreed through the Waste Framework Directive 2008/98/EC, that at least 70% of construction and demolition waste should be recycled by 2020. From recycling plants, three types of recycled aggregates are produced. Recycled Concrete Aggregate, mainly from cementitious waste, as such as concrete and mortars residues; Recycled Masonry Aggregates mainly composed by recycled ceramic materials, as such as tiles and bricks residues; Mixed Recycled Aggregates based on rubble residues, from heterogenous materials waste. This research evaluated the technical feasibility of rendering mortars with Recycled Concrete Aggregates and Mixed Recycled Aggregates, in different volume incorporation of 0%, 20%, 50% and 100%. The experimental programme comprised an analyse of the fresh and hardened properties, regarding the water and mechanical behaviour of the mortars. From the results, it was noticed that the modified mortars presented a reduction in the modulus of elasticity, which its correlated to a less susceptibility to cracking. Regarding mechanical performance, the modified mortars obtained reduction of the flexural and compressive strength over time. However, it was not a significant harmful criterion. Therefore, the incorporation of recycled aggregates in cementitious materials is considered a technical and sustainable solution.

scholarly journals Materiale compozite pe baza de deseuri de beton celular autoclavizat si rasina poliesterica nesaturata

2019 ◽  
Vol 56 (1) ◽  
pp. 256-260
Author(s):  
Gelu Coman ◽  
Gabriel-Bogdan Carp ◽  
Ion Ion ◽  
Alina Ceoromila ◽  
Nicusor Baroiu
Keyword(s):  
Thermal Conductivity ◽  
Composite Material ◽  
Thermal Resistance ◽  
Water Absorption ◽  
Unsaturated Polyester ◽  
Absorption Capacity ◽  
Insulation Material ◽  
Water Absorption Capacity ◽  
The Matrix ◽  
Influence Of Water

This paper presents an experimental study on the potential use of new type of composite as insulation material. The composite material (AACW-UPR) was synthesised through mixture between the Autoclaved Aerated Concrete Waste (AACW) as filler and Unsaturated Polyester Resin (UPR) as matrix. Several samples of the composite material with different UPR concentrations (50 and 70 vol.%) and different AACW particle size (0.2-1 mm, 1.5-2.5 mm, 3-6 mm) were prepared. The thermal behaviour and the water absorption capacity of the AACW-UPR composite materials were studied. Also, the influence of water absorption capacity on thermal resistance and thermal conductivity was studied. During the investigations we noticed the following: good chemical compatibility between the AACW particles and the UPR matrix; a decrease in thermal conductivity for samples with 50 vol.% UPR and inserted particles size between 3-6 mm and an increase in water absorption capacity with the increase in the filler content in the matrix. The increasing water absorption capacity determined a decrease in thermal resistance and a reduction of the composite features as insulating material.

scholarly journals The Production of Sustainable Concrete with the Use of Alternative Aggregates: A Review

2020 ◽  
Vol 12 (19) ◽  
pp. 7903
Author(s):  
Maria Cristina Collivignarelli ◽  
Giacomo Cillari ◽  
Paola Ricciardi ◽  
Marco Carnevale Miino ◽  
Vincenzo Torretta ◽  
...  
Keyword(s):  
Alternative Fuels ◽  
Waste Treatment ◽  
Mechanical Performance ◽  
Raw Materials ◽  
Metallurgical Industry ◽  
Construction And Demolition Waste ◽  
Demolition Waste ◽  
Core Element ◽  
Complete Replacement ◽  
Coarse Aggregates

The concrete industry is a core element of the building sector, but it has to deal with the increasing attention on the environmental issues related to the production process: increasing energy efficiency and the adoption of alternative fuels or raw materials represent the most relevant solutions. The present work analyses physical, mechanical, and environmental performances of concrete incorporating residues derived from four main sources (construction and demolition waste, residues from waste treatment, metallurgical industry by-products, and others), as substitutes of either fine or coarse aggregates. Fine aggregates showed the highest number of alternatives and replacement level, with the relevant impact on concrete properties; coarse aggregates, however, always reach a complete replacement, with the exclusion of glass that highly affects the mechanical performance. Construction and metallurgical industry categories are the main sources of alternative materials for both the components, with ceramic and lead slag reaching a full replacement for fine and coarse aggregates.

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