Strength properties of polymer mortar panels using methyl methacrylate solution of waste expanded polystyrene as binder

The present study examines the applicability of polymermortarpanels using a methylmethacrylate (MMA) solution of wasteexpandedpolystyrene (EPS) to develop effective recycling processes for the EPS, referring to the strengthproperties of a polymer-impregnated mortarpanel with almost the same performance as commercial products. An MMA solution of EPS is prepared by dissolving EPS in MMA, and unreinforced and steel fiber-reinforced polymermortars are mixed using the EPS-MMA-based solution as a liquid resin or binder. Polymermortarpanels (PMPs) using the EPS-MMA-based polymermortars without and with steel fiber and crimped wire cloth reinforcements and steel fiber-reinforced polymer-impregnated mortarpanel (PIMP) are prepared on trial, and tested for flexural behavior under four-point loading. The EPS-MMA-based PMPs are more ductile than the PIMP, and have a high load-bearing capacity. Consequently, they can replace PIMP in practical applications

Recent Status of Research and Development of Concrete-Polymer Composites in Japan

The present paper reviews the recent status of research and development activities of concrete-polymer composites such as polymer-modified concrete (mortar), polymer concrete (mortar) and polymer-impregnated concrete (mortar) in the Japanese construction industry. Polymer-modified concrete (mortar) comprise of repair systems for deteriorated reinforced concrete structures, strengthening (or retrofitting) methods and exfoliation (or delamination) prevention methods for existing reinforced concrete structures, liquid-applied membrane waterproofing systems, advanced polymeric admixtures such as high-grade redispersible polymer powders and  hardener-free epoxy resins, intelligent repair materials, application of accelerated curings, semiflexible pavements, and drainage pavements with photocatalyst. Polymer mortar and concrete are related to new liquid resins, setting shrinkage control, thermal properties and temperature dependence, lightweight or porous polymer mortars and concretes, artificial marble products and precast products. The polymer-impregnated mortar and concrete are mainly concerned with field polymer impregnation techniques using silane-based barrier penetrants

Mix design and compressive strength of geopolymer concrete containing blended ash from agro-industrial wastes

Geopolymer concrete is a type of amorphous alumino-silicate cementitious material. Geopolymer can be polymerized by polycondensation reaction of geopolymeric precursor and alkali polysilicates. Compared to conventional cement concrete, the production of geopolymer concrete has a relative higher strength, excellent volume stability and better durability. This paper presents the mix design and compressive strength of geopolymer concrete manufactured from the blend of palm oil fuel ash (POFA) and pulverized fuel ash (PFA) as full replacement of cement with a combination of sodium silicate and sodium hydroxide solution used as alkaline liquid. The density and strength of the geopolymer concrete with various PFA: POFA ratios of 0:100, 30:70, 50:50 and 70:30 together with sodium silicate to sodium hydroxide solution by mass at 2.5 and 1.0, are investigated. The concentrations of alkaline solution used are 14 Molar and 8 Molar. Tests were carried out on 100×100×100 mm cube geopolymer concrete specimens. Specimens were cured at room temperature and heat curing at 60°C and 90°C for 24 hours, respectively. The effects of mass ratios of PFA: POFA, the alkaline solution to PFA: POFA, ratio and concentration of alkaline solution on fresh and hardened properties of concrete are examined. The results revealed that as PFA: POFA mass ratio increased the workability and compressive strength of geopolymer concrete are increased, the ratio and concentration of alkaline solution increased, the compressive strength of geopolymer concrete increases with regards to curing condition

Properties of polymer modified mortars

The using of epoxy resin as repair material in concrete is quite common. Previous research proof that epoxy resin in concrete can give strength and have high durability towards aggressive environment. Usually epoxy resin needs a hardener to make it hard when mix with concrete but in this research, the development of concrete by using epoxy resin without hardener is investigate. Epoxy resin without hardener or can be known as epoxy-modified mortar also can mix well with cement and harden the concrete. This is due to the present of hydroxide ion in cement hydrate that can react with epoxy resin and make it harden. This paper is present a strength properties of epoxy-modified mortar up to three months. In this research an epoxy resins (Diglycidyl Ether of Bisphenol A) without any hardener is used as polymeric admixture to prepare polymeric-cementitious materials and their strength properties are analysed. Epoxy-modified mortars are prepared with various polymer-cement ratios, subjected to initial wet/dry curing plus long term dry. The optimum mix proportion of epoxy resin content in concrete is determined. The result shows that, the optimum polymer to cement ratio is 10% with dry/wet curing and up to three month of strength development, the compressive strength continuously increased

Strength properties and molecular composition of epoxy-modified mortars

Even without hardener, epoxy resin is able to harden in the presence of hydroxyl ions produced during cement hydration process. In this study commercially available Bisphenol A-type epoxy resin without hardener was used as a polymeric admixture to prepare epoxy-modified mortars, whose properties and chemical composition were then investigated. The mortars were prepared with a mass ratio of 1:3 (cement:fine aggregate), water-to-cement ratio (W/C) of 0.48, and epoxy content of 5%, 10%, 15% and 20% of cement. The specimens were subjected to dry and wet-dry curing. Workability, setting time, compressive strength, flexural strength, and tensile splitting strength tests were conducted. A Fourier transformation infrared spectroscopy test was also administered to determine the molecular composition and structure of mortars. Results showed an inverse relationship between workability and setting time of mortars versus epoxy content. The compressive, flexural, and tensile splitting strengths of epoxy-modified mortars were noted to be the highest for mortars containing 10% epoxy in wet-dry curing. A significant improvement in strength development of mortars without hardener had been achieved through dry curing due to gradual hardening of epoxy resin with hydrated cement

Effects of polymer-cement ratio and accelerated curing on flexural behavior of hardener-free epoxy-modified mortar panels

This experimental study reports the applicability of hardener-free epoxy-modified mortar panels to permanent forms as precast concrete products. Hardener-free epoxy-modified mortars are mixed using a Bisphenoal A-type epoxy resin without any hardener with various polymer–cement ratios and steel fiber reinforcement, and subjected to different curings. Hardener-free epoxy-modified mortar panels are prepared with same polymer–cement ratios and steel fiber reinforcement on trial, and tested for flexural behavior under four-point (third-point) loading. The effects of polymer–cement ratios and curings on strength properties of hardener-free epoxy-modified mortars, and on the flexural strength, flexural stress-extreme tension fiber strain relation, flexural load–deflection relation of hardener-free epoxy-modified mortar panels were examined. The adhesion in tension (to placed concrete) of the hardener-free epoxy-modified mortar panels was also tested. As a result, the hardener-free epoxy-modified mortar panels develop a high flexural strength, large extensibility and good adhesion to the placed concrete. The epoxy-modified mortar panels are more ductile and have high load-bearing capacity than unmodified mortar panels and can be used as precast concrete permanent forms in practical applications

Air permeability of hardener-free epoxy-modified mortars using NDT

The purpose of this study is to investigate the air permeability of hardener-free epoxymodified mortars by applying a non-destructive testing method developed by RILEM Technical Committee 189-NEC. Considering intelligent patch materials for the repair work of deteriorated reinforced concrete structures, hardener-free epoxy-modified mortars using a bisphenol A-type epoxy resin without any hardener are prepared with various polymercement ratios, and tested for moisture content, air permeability and strength. As a result, although there is no significant strength improvement, the coefficient of air permeability of the hardener-free epoxy-modified mortars is markedly decreased with an increase in the polymer-cement ratio

Influence of non-hydrocarbon substances on the compressive strength of natural rubber latex-modified concrete

Inclusion of polymeric substances into hydraulic cement concrete has made a tremendous impact towards improving its performance properties. However, polymers to be included into concrete should neither cause damage to its mechanical capacities nor to its durability characteristics. This article reports experimental findings regarding influence of non-hydrocarbon substances present in natural rubber latex (NRL) on the compressive strength of NRL-modified concrete. Six selected clonal latexes were chemically analyzed for thirteen compositional parameters each. The latexes are used in making modified concretes and specimens obtained from these concretes were given both moisture and dry curing treatments for effective cement-hydration and latex-film formations respectively. Eventually, concretes modified with latexes containing higher non-hydrocarbon substances especially volatile fatty acids (VFA) and zinc were observed to suffer significant compressive strength losses. Indeed, 12.4% loss in compressive strength was recorded against concrete modified with the latex having the highest contents of VFA and zinc. However, 2% and 4% increase in the strength over normal concrete were observed in relation to two of the latexes investigated

Recent status of research and development of concrete-polymer composites in Japan

The present paper reviews the recent status of research and development activities of concrete-polymer composites such as polymer-modified concrete (mortar), polymer concrete (mortar) and polymer-impregnated concrete (mortar) in the Japanese construction industry. Polymer-modified concrete (mortar) comprise of repair systems for deteriorated reinforced concrete structures, strengthening (or retrofitting) methods and exfoliation (or delamination) prevention methods for existing reinforced concrete structures, liquid-applied membrane waterproofing systems, advanced polymeric admixtures such as high-grade redispersible polymer powders and hardener-free epoxy resins, intelligent repair materials, application of accelerated curings, semiflexible pavements, and drainage pavements with photocatalyst. Polymer mortar and concrete are related to new liquid resins, setting shrinkage control, thermal properties and temperature dependence, lightweight or porous polymer mortars and concretes, artificial marble products and precast products. The polymer-impregnated mortar and concrete are mainly concerned with field polymer impregnation techniques using silane-based barrier penetrants