Future outlooks and challenges of sustainable lightweight composites

A feasibility study was performed to utilize struvite, in combination with magnesium oxide (MgO), to develop magnesium phosphate cement. The struvite was a wastewater by-product from a sewage treatment plant in British Columbia, Canada. To achieve MgO-phosphate reactivity in water, two types of recycled struvite were used: heated struvite and newberyite (i.e. rehydrated struvite). A more common phosphate source, Potassium Dihydrogen Phosphate (KDP) was also adopted and replaced in different proportions by recycled struvite. Perlite was incorporated to produce lightweight composites for building applications at different strength-density ratios. Microstructural/chemical analyses were complemented with compressive strength tests at different ages. Reactivity with MgO was achieved for both heated struvite and newberyite. The main reaction product was cattite but reactivity of less soluble newberyite was lower. KDP had the fastest reaction leading to the formation of K-struvite. The lightweight composites achieved up to 90% of their strength in 7 days.

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Development and characterization of sustainable lightweight geopolymer composites

Cerâmica ◽

10.1590/0366-69132019653732551 ◽

2019 ◽

Vol 65 (373) ◽

pp. 153-161 ◽

Cited By ~ 1

Author(s):

H. M. Khater

Keyword(s):

Compressive Strength ◽

Water Absorption ◽

Aluminum Powder ◽

Building Materials ◽

Microstructural Characteristics ◽

Imaging Results ◽

Lightweight Composites ◽

Sem Imaging ◽

Geopolymer Composites

Abstract Production of lightweight building materials attract the attention of the scientists worldwide with the need for reducing the structure deadweight, provide better thermal insulation for buildings, and cost less to transport. The current work focused on the production of lightweight geopolymer composites by the incorporation of aluminum powder and aluminum slag in various ratios for water-cooled slag/kaolinite sand composite; the activators used were 6% of equal ratio from sodium hydroxide and sodium silicate. The properties of the produced lightweight geopolymer composites were studied by measurement of compressive strength, bulk density, water absorption, FTIR, XRD and SEM imaging. Results showed the enhancement for both physicomechanical and microstructural characteristics with using aluminum powder and aluminum slag forming lightweight composites with densities below 2.15 g/cm3 depending on the studied mix composition.

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Experimental Study of the Recycled Plastic Aggregate Lightweight Composites Based on Different Kinds of Binder

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.868.32 ◽

2020 ◽

Vol 868 ◽

pp. 32-38

Author(s):

Valéria Gregorová ◽

Zuzana Štefunková ◽

Miriam Ledererová

Keyword(s):

Thermal Conductivity ◽

Compressive Strength ◽

Bulk Density ◽

Thermal Conductivity Coefficient ◽

Negative Impact ◽

Cement Composites ◽

Ethyl Vinyl ◽

Cement Binder ◽

Lightweight Composites ◽

Recycled Waste

In this paper, the selected properties of lightweight composites based on the different kinds of binder and recycled waste plastics aggregate were studied. Plastic waste e.g. foamed polystyrene, polypropylene, polyurethane foam or ethyl vinyl acetate (EVA) as an aggregate in these composites was used. Cement CEM II B/S 32.5 R and an organic-based adhesive with the business name Conipur 360 were used as a binder. The cement composites consisted of constant water to cement ratio 0.50 and dose of cement 175 kg/m3. Mixtures of adhesive composites were prepared with constant dose of adhesive 100 kg/m3. The kind of recycled waste aggregate was only changed. The physical properties, such as bulk density, compressive strength and thermo-technical properties were verified. The application of organic-based adhesive resulted in a significant decreasing values of the bulk density (100 kg/m3 - 230 kg/m3) and the thermal conductivity coefficient (0.0511 W/m.K - 0.0686 W/m.K) of lightweight composites. The negative impact of this type of binder resulted to a decreasing value of the compressive strength (0.15 MPa - 0.32 MPa). Use of cement binder caused to an increasing of bulk density (290 kg/m3 - 375 kg/m3) and worsening of the thermal conductivity coefficient of these composites (0.0660 W/m.K - 0.0799 W/m.K). The compressive strength values of cement composites ranged from 0.24 MPa to 0.50 MPa.

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Fabrication of novel lightweight composites by a hydrogel templating technique

Materials Research Bulletin ◽

10.1016/j.materresbull.2012.01.014 ◽

2012 ◽

Vol 47 (4) ◽

pp. 980-986 ◽

Cited By ~ 19

Author(s):

Marius Rutkevičius ◽

Sellva K. Munusami ◽

Zoe Watson ◽

Adam D. Field ◽

Michelle Salt ◽

...

Keyword(s):

Lightweight Composites ◽

Templating Technique

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Possibilities of Using Alternative Materials as a Substitute Binder or Filler into Composites

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1105.31 ◽

2015 ◽

Vol 1105 ◽

pp. 31-35 ◽

Cited By ~ 1

Author(s):

Nadežda Števulová ◽

Ivana Schwarzova ◽

Viola Hospodarova ◽

Jozef Junak ◽

Marcela Ondova ◽

...

Keyword(s):

Compressive Strength ◽

Fly Ash ◽

Coal Fly Ash ◽

Steel Slag ◽

Recycled Concrete ◽

Partial Replacement ◽

Alternative Materials ◽

Activated Coal ◽

Hemp Fibres ◽

Lightweight Composites

This article reports on the possibilities of using selected alternative materials like hemp fibres, MgO-cement, recycled concrete, fly ash and steel slag as binder or filler replacement in composite materials in civil engineering production. These binder or filler substitutes were mixed into composites and their compressive strength was tested. The paper is divided into four parts providing the results of experiments. In first part strength parameters of lightweight composites based on natural fibres (hemp hurds) and alternative binder (MgO-cement) are presented. Compressive strength values of concrete samples with partial replacement of cement with mechanochemically activated coal fly ash are given. The third and forth part is aimed to utilization of recycled concrete and steel slag as a natural aggregate replacement in concrete mixture for purpose of structural concrete and surface roads.

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