Binder Mortar Research Articles

Short-Term Compressive Strength of Fly Ash and Waste Glass Alkali-Activated Cement-Based Binder Mortars with Two Biopolymers

AbstractThe Roadmap to a Resource Efficient Europe aims that by 2020, waste will be managed as a resource. Thus materials that have the ability for the reuse of several types of wastes, such as alk...

다양한 물-결합재비를 갖는 모르타르의 물성에 대한 파쇄 바텀애시의 영향

최대 입경 1 mm 이하의 파쇄 바텀애시 혼입이 다양한 물-결합재비를 갖는 모르타르의 성능에 미치는 영향 확인하였다. 이는 파쇄 바텀애시를 혼입한 모르타르 및 콘크리트의 배합설계기법을 성립하기 위한 기초연구로서 수행된 것이다. 모르타르의 유동성 및 공기량, 압축강도가 측정되었다. 배합설계기준인 28일 압축강도를 기반으로 CEN/TR 16637에서 제안한 등가압축강도 개념을 고려하여 파쇄 바텀애시의 강도기여 효율을 평가하였다. 실험결과, 파쇄 바텀애시가 우수한 결합재로서의 역할을 하는 경우도 있는 반면, 골재에 가까운 역할을 하는 경우도 있음을 확인하였다. 파쇄 바텀애시의 효율은 바텀애시의 종류 및 치환률, 모르타르의 w/의 변화에 따라 달라진다. Effects of crushed coal bottom ash (CBA) with maximum size of 1 mm on the properties of mortar with various water-to-binder ratios (w/b) were evaluated. The present work is a fundamental study to establish a method of mix proportion design for mortar and concrete with CBA. The workability, air contents, and compressive strength of mortar were measured. Efficiency of CBA on the compressive strength at 28 days, which was adopted for mix proportion design, was evaluated based on concepts of 'equivalent strength' in CEN/TR 16637. It was found that the CBA could be contributed as a binder in mortar in some cases, while in other cases act as at aggregates. The efficiency of CBA was influenced by types of CBA and their replacement ratio, and w/b of mortar.

Selection of thinner for epoxy–amine system used as binder for polymeric mortars

ABSTRACTEpoxy resin mortars are mainly used in the implementation of precast items used in the civil engineering field. The workability of these mortars represents a major obstacle to the development of this field. In order to improve this property, different types of thinners are selected to study their effect on the rheological properties of the epoxy–amine system. Rheological tests are performed in order to estimate the resin gel point and to measure its viscosity during the crosslinking reaction. It appears that viscosity is the lowest for mixtures prepared with methyl octanoate, o‐xylene, and butyl glycidyl ether. Methyl octanoate is chosen as an ecofriendly thinner. The curing process is evaluated by varying the amount of the selected thinner using isothermal and dynamic DSC to determine the end of crosslinking. The mechanical properties using dynamic mechanical analysis (DMA) and tensile resistance testing of the cured epoxy resin with different amounts of methyl octanoate are also investigated. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43970.

Mechanical strength development of mortars containing volcanic scoria-based binders with different fineness

The benefits of using natural pozzolan as cement replacement are often associated with shortcomings such as the need to moist-curing for longer time and a reduction of strength at early ages. The objective of the study is to investigate the influence of binder fineness on the mechanical strength development of scoria-based binder mortars. In the study, mortar specimens have been produced with four types of binder: one plain Portland cement (control) and three scoria-based binders with three replacement levels: 25%, 30% and 35%, respectively. All scoria-based binders have been inter-ground into four different Blaine fineness: 2400, 3200, 4200 and 5100 cm2/g. The development of the compressive and flexural tensile strength of all mortar specimens with curing time has been investigated. The effects of the Blaine fineness of the scoria-based blended cement on the compressive and flexural strengths of mortar have been evaluated at curing ages of 2, 7, 28 and 90 days, respectively. Particle size distribution measured by a laser diffractometer has been considered in the study. Test results revealed that there is a decrease in strength with increasing amounts of scoria. In addition, there was found an increase in strength with increasing the Blaine fineness values. No direct relationship between Blaine and particle size distribution was observed. Effects of Blaine fineness on some physical properties of blended cements such as water demand, setting times and soundness have also been investigated. Further, an estimation equation for strength development incorporating the effects of fineness measured either by Blaine or by particle size distribution has been derived by the authors.

Organic montmorillonite reinforced epoxy mortar binders

In this work, in order to investigate the reinforcement effects of organic montmorillonite (OMMT) modified epoxy mortar binders (EMBs), a series of OMMT/EMB composites with different OMMT loadings were prepared. The structure and thermal stability of OMMT were studied by X-ray diffraction (XRD), Fourier transform infrared spectrum, and thermogravimetric analysis (TGA). The effects of OMMT on the structure, glass transition, damping properties, thermal stability, mechanical properties and morphology of EMB were characterized by XRD, dynamic mechanical analysis, TGA, tensile test, and scanning electron microscopy. XRD results indicated that epoxy chains intercalated into the OMMT layers and led to the expansion of OMMT layer spacing. The presence of OMMT increased the glass transformation temperature, crosslink density of the neat EMB. Furthermore, the incorporation of OMMT improved the thermal stability of the EMB. The OMMT/EMB composites showed higher tensile strength and Young’s modulus than the neat EMB. Homogenous dispersion of OMMT in EMB matrix was observed.

An Alkali Activated Binder for High Chemical Resistant Self-Leveling Mortar

This paper reports the development of an Alkali Activated Binder (AAB) with an emphasis on the performance and the durability of the AAB-matrix. For the development of the matrix, the reactive components granulated slag and coal fly ash were used, which were alkali activated with a mixture of sodium hydroxide (2 - 10 mol/l) and aqueous sodium silicate solution (SiO2/Na2O molar ratio: 2.1) at ambient temperature. A sodium hydroxide concentration of 5.5 mol/l revealed the best compromise between setting time and mechanical strengths of the AAB. With this sodium hydroxide concentration, the compressive and the 3-point bending tensile strength of the hardened AAB were 53.4 and 5.5 MPa respectively after 14 days. As a result of the investigation of the acid resistance, the AAB-matrix showed a very high acid resistance in comparison to ordinary Portland cement concrete. In addition, the AAB had a high frost resistance, which had been validated by the capillary suction, internal damage and freeze thaw test with a relative dynamic E-Modulus of 93% and a total amount of scaled material of 30 g/m2 after 28 freeze-thaw cycles (exposure class: XF3).

Properties of different particle size of recycled TFT-LCD waste glass powder as a cement concrete binder

In the high-tech industry in Korea, the use of thin-film transistor liquid-crystal display (TFT-LCD) glass products has increased significantly in recent years and large amounts of TFT-LCD waste glass are produced during the manufacturing process. The use of recycled waste glass in Portland cement and concrete has attracted a lot of interest worldwide due to environmental concerns, and the increased cost of disposing of used glass. This research studied the effect of different particle size of grinding TFT-LCD waste glass proportions on binder in cement mortar. Experiments were conducted to determine the optimal replacement content and particle type to ensure that the quality of concrete products is maintained. The results indicate that the use of TFT-LCD waste glass powder as an admixture for cement mortar was efficient in reducing alkali–silica reaction (ASR) expansion and increasing workability. The compressive strength of mortars with TFT-LCD waste glass was also improved compared with that of normal mortar, due to the increased amount of calcium silicate hydrates created by pozzolanic reaction. But it was apparent that the properties of workability, compressive strength and ASR were different significantly with particle size of TFT-LCD waste glass powder.

Pore-related properties of natural hydraulic lime mortars: an experimental study

Restoration of historic buildings is often executed using lime mortars. A restoration mortar is considered compatible with the original building materials when it answers to certain criteria, such as the facilitation of moisture transport. This can be determined by studying porosity, permeability, and the pore size distribution of both materials. Since NHL mortars are used in restoration of the exterior, where water and moisture are ever-present, a good characterization in terms of their pore-related properties is necessary. This study therefore researched characteristics of pure NHL mortars, without metakaolin or pozzolan additives. In this study, 16 different mortar recipes were made with NHL 5, the most hydraulic NHL type. The mortars had variations in spread, sand type and grain size. The sand types varied from coarse-grained to very fine, in order to be able to study the influence of the largest and smallest grains. The spread was adapted from 120 to 180 mm by changing the water:binder ratio. This allows understanding the influence of binding water on these pore-related properties. The measured pore-related properties were linked to compressive strength measurements, so as to characterize these eminently hydraulic limes also on a mechanical level. Nearly 180 samples were tested after 90 days of curing. All mortars show a bimodal pore size distribution. Depending on the sand type and the mortar spread, the mechanical strength varied from 1 to 10 MPa and pore sizes varied from the larger to smaller pore region. This demonstrates the large influence aggregates and water have on the properties of the hardened mortar. In general, the influence of the variation in water:binder ratio was less apparent, although an excess of binding water was translated into a change towards smaller pores, higher porosity and lower compressive strength. This study demonstrates that NHL 5 lime can be a good binder for restoration mortars, in which the properties of the mortar can be adapted through variation of aggregate grain size and spread. This allows researching a possible estimation of properties before making the mortars.

The properties of cement-based mortar using different particle size of grinding waste insulator powder

Insulators used for high-voltage power transmission are made from ceramic, glass, porcelain or composite polymer materials. Ceramic and porcelain goods are produced from natural materials containing a high proportion of clay minerals. And waste insulator can be used as an active additive thanks to their pozzolanic properties, or as recycled aggregate in the manufacture of mortars and concrete. This research studied the effect of different particle size of grinding waste insulator proportions on binder in cement mortar. Experiments were conducted to determine the optimal replacement content and particle type to ensure that the quality of concrete products is maintained. The results indicate that the use of grinding insulator powder as an admixture for cement mortar was efficient in increasing compressive strength, workability and in reducing alkali silica reaction expansion due to the increased amount of calcium silicate hydrates created by pozzolanic reaction. And it was apparent that the properties of mortar were different with particle size of grinding insulator powder.

Brucite modified epoxy mortar binders: Flame retardancy, thermal and mechanical characterization

Polymer mortar with excellent mechanical strength and durability has been widely used in road pavement and other construction industry. In this study, two kinds of brucites, synthetic and natural brucites were incorporated in the epoxy mortar binders as flame retardants. The components and morphology of the two kinds of brucites were investigated. The flame retardancy of brucite-modified epoxy mortar binders was evaluated by the horizontal burning and limiting oxygen index tests. The influence of flame retardants on the rotational viscosity, the thermal and mechanical properties of epoxy mortar binders was determined by differential scanning calorimetry, thermogravimetric analysis, and universal test machine. Furthermore, the morphology of flame retarded-epoxy mortar binders was characterized by scanning electron microscopy. The addition of brucites significantly improved the flame retardancy, thermal stability and tensile strength of epoxy mortar binders. Especially in the case of the addition of 20wt% synthetic brucites in epoxy mortar binders, from FH-3 to FH-1 reduction in the horizontal burning classification, 5.5% improvement in limiting oxygen index, 15% increment in tensile strength were obtained.

Characterization of historical mortars from the bell tower of St. Nicholas church (Pisa, Italy)

The aim of this research is to characterize the binder and aggregate fractions of sixteen mortar samples from the bell tower of the St. Nicholas church at Pisa, using X-ray fluorescence (XRF), X-ray powder diffraction (XRPD), simultaneous thermogravimetric/differential scanning calorimetry analysis (TG/DSC), optical microscopy (OM) and electron microscopy equipped with a microanalysis system (SEM/EDS).The analytical procedure used for studying the mortars is based on TG/DSC analyses performed on the binder fractions, obtained by disaggregation of the mortar samples, and on micro-analytical data directly collected on the mortar binders combined with chemical, mineralogical (qualitative composition) and petrographic (modal composition) data measured on the bulk mortar samples.The collected data indicate that the examined samples are hydraulic lime mortars with natural river sands (average binder/aggregate ratio 1:1), except for two of them which are artificial pozzolanic mortars with cocciopesto. The most probable raw materials used to produce the mortars are the binding materials obtained by firing carbonate rocks locally available, cherty limestone and subordinately Mt. Pisano marble, and the Arno River sands or, more likely, natural admixtures of Arno and Serchio River sandy sediments.

A study of the effect of corrosive solutions on selected physical properties of modified epoxy mortars

A partial replacement of resin binder in epoxy mortars by PET waste based glycolyzates makes these building materials ecologically and economically interesting. The article presents the results of the first phase of research on epoxy mortars modified with poly(ethylene terephthalate) (PET) glycolyzates. Changes of some chosen mortar parameters (weight change, appearance of mortar specimens) due to the effect of the solutions of five aggressive media were monitored for twelve months. It was established that unlike ordinary cement mortars, the building composites that were obtained showed very good chemical corrosion resistance. The results of the investigation were presented as the trend function.

Reactivity of Brick Powder in Lime Mortars

The article deals with the assessment of three brick powders. Their properties are evaluated on the basis of their pozzolanic activity, specific surface area and amorphous area. The brick powders were used in amounts of 20 and 40% as a substitute for binder in lime mortars. The influence of the powders on the properties of the modified plasters in a hardened state was evaluated via the determination of strength characteristics. It was found that not all brick powders are suitable for use in modified lime mortars.

Mechanical Properties of Composite Mortars Using Flurogypsum and PVC Particles

The present work describes the viability of a mortar binder based on two industrial by-products: poly(vinyl chloride) (PVC) particles from scrap and anhydrite (CaSO4) from fluorgypsum. Mortar composites were made incorporating different amounts of PVC particles and cured at constant room temperature during various periods of time. From X-ray diffraction, it was possible to follow the hydration process and to estimate the effect of the PVC particles on anhydrite transformation to gypsum (CaSO4·2H2O). Compressive strength from uniaxial testing was measured from stress-strain curves carried out at room temperature. According to these results, the hydration rates of the composites depend on the concentration of PVC particles and there is an enhancement in their compressive strength as particle content increases, reaching values of 36 MPa after 28 days.

Replicating the chemical composition of the binder for restoration of historic mortars as an optimization problem

The present study aims to show how the problem of reproducing, as closely as possible, binders of historic mortars by mixing raw materials which are commercially available, can be formulated as a linear optimization problem. The study points out that by mixing five standard raw materials (end-members) it is possible to obtain mortar binders with the almost same chemical compositions of those determined on the historic and archaeological mortar samples studied in some recent scientific papers. An advanced function of the Microsoft Excel spreadsheet, the Solver add-in, was used for the calculation of the right amount of each raw material to be mixed for producing the new binders. This approach could be useful to provide an optimal solution in the process of restoration of ancient monuments, where it is necessary to replace the historic mortars with new highly compatible repair mortars.

The fluid transport properties of HCWA–DSF hybrid supplementary binder mortar

It has been demonstrated in several past studies that high calcium wood ash (HCWA) can be effectively used in combination with densified silica fume (DSF) as supplementary binder material to enhance the mechanical performance of concrete. The experimental investigation was conducted to study the effect of the inclusion of HCWA and DSF on the durability properties of high strength cement mortar produced. A total of twelve different mix designs of mortar were fabricated with the use of HCWA at various cement replacement levels of 0–20% in combination with 7.5% densified silica fume (DSF) and subjected to various durability tests. The durability assessments performed include tests on water absorption, air permeability, porosity and degree of carbonation. A significantly lower degree of water absorption, porosity and carbonation was observed for cement mortars with HCWA contents of 2–8% used in combination with 7.5% DSF by weight of binder as compared to an equivalent pure cement mortar.

Dolomitic Lime in the US

This paper presents the findings of a comparative study of the physical and chemical properties of dolomitic (magnesian) and high calcium lime mortars with respect to their use for the construction and repair of buildings. Dolomitic hydrated lime has been widely used in the United States as a binder in masonry mortar for over 70 years. Investigation of the curing process of dolomitic lime and how the chemistry affects the physical properties of the mortar has yielded new information. Dolomitic lime mortar behaves differently than mortar containing high calcium lime, yet in the US often no distinction is made between them. With the advent of new machinery for hydrating dolomitic lime in the 1940s, it could be more easily hydrated, packaged and sold. This product enjoyed great popularity during the second half of the twentieth century, particularly as a binder in repointing mortars.

Feasibility of Basalt Fiber Reinforced Inorganic Adhesive for Concrete Strengtening

Phosphate based binders are high early strength materials with a short setting time. Usually, they are used as rapid repair material for concrete structures. The feasibility of a basalt fiber reinforced inorganic binder for strengthening concrete was studied. We successfully compounded suitable phosphate binder (PB) for concrete strengthening. In the current paper, phosphate binder was to adjusted to has excellent workability, suitable setting time and fluidity. Compressive strength of phosphate binder mortar, bonding strength between PB and Portland cement mortar, and strengthening effect of PB sticked basalt fiber on concrete beam were measured. Results showed that PB has excellent adhesion with Portland cement mortar. The strengthening effect of basalt fiber reinforced PB composite on concrete beam is evident. It is feasible that concrete strengthening by basalt fiber reinforced inorganic adhesive.

Unravelling Porous Asphalt Concrete, Towards a Mechanistic Material Design Tool

ABSTRACT PA (Porous Asphalt Concrete) is the standard surfacing material for the Dutch primary road network. More than 70% of this network is surfaced with PA. Ravelling, the loss of stone from the road surface, is in most cases by far decisive for PA service life. Ravelling resistance is mainly generated by the PA mixture performance and not by the pavement's structural design. This paper discusses the development and validation of a mechanistic Lifetime Optimization Tool for PA, LOT. LOT is based on Finite Element (FE) modelling on meso scale, i.e. the scale of stone chippings. Laboratory tests performed to obtain insight into the behaviour of PA mortar (binder) and the adhesive zones that bond stone to mortar are discussed. The forces acting on individual stones at the surface during the passage of a tyre are also discussed in the paper. Also FE models of the PA mixture's structural geometry are discussed. At the end of the paper validation of LOT brings it all together. For validation purposes full-scale ravelling tests, were done at STUVA in Germany. The tests considered four PA mixtures. For each mixture LOT calculations are compared to real PA performance. This validation indicates a very strong correlation between LOT and full-scale PA performance.

혼화제.재가 무시멘트 황토 모르타르의 유동성 및 압축강도 발현에 미치는 영향

This paper reports test results to assess the influence of superplasticizers and different admixture on the flow and compressive strength development of cementless mortar using developed hwangtoh binder. Test specimens were classified into four groups: series for I the mixing ratio of superplasticizers, series II for a kind and replacement level of admixtures according to the variation of water/hwangtoh binder ratio, series III for the specific surface area and replacement level of ground granulated blast-furnace slag and series IV for the replacement level of powered superplasticizer agent developed to improve slump loss of concrete. The proper replacement level of each admixture is proposed for enhancement the flow and compressive strength of the hwangtoh binder mortar.