Types Of Mortars Research Articles

Workability Strength and Elastic Properties of Cement Mortar with Pond Ash as Fine Aggregates

Natural sand obtained from river beds are normally used as fine aggregates in preparation of cement mortar. Due to increased demand and excessive extraction of river sand; there is an acute shortage in different parts of the world. Various research agencies are striving to investigate the properties of mortar with alternate fine aggergates such as M-sand, Pond ash, slag sand etc. Present study investigates flow, strength, density and elastic properties of cement mortar at various replacement levels of alternate fine aggregate, Pond Ash. Masonry and two types of plastering mortars were prepared with river sand as fine aggregate. Flow characteristics of masonry and plastering mortar were studied till attainment of flow of 85 and 110% respectively. River sand was replaced by pond ash at replacement levels of 20, 40, 60, 80, and 100% and flow test was conducted. Effect of replacement on flow characteristics was studied. Mortar cubes and prisms were cast and tested for compressive strength and Modulus of elasticity. Results indicate that water cement ratio required to attain the target flow increases with pond ash. The compressive strength of mortar decreases with increase of pond ash. Reduced density and modulus of elasticity were observed in pond ash mortar when compared to river sand mortar. Hence pond ash can be used as an alternate to river sand in production of lean mortar and blocks

Characteristics and Application of Thermal Mortar Materials in Building Materials

Abstract This paper first defines the concept of thermal mortar material, introduces thermal mortar types, and explains the difference between thermal mortar and other insulation materials. Then, it further analyzes the difference between mixing ratios of thermal mortar and traditional concrete. This paper concludes that thermal mortar has certain advantages in insulation building materials. Where, Thermal insulation glazed hollow bead mortar as a new inorganic thermal mortar material has superior performance and characteristics, and enjoys a broader market prospect.

Predicting the mechanical properties of lightweight aggregate concrete using finite element method

Abstract The compressive strength (fc) and Young’s modulus (Ec) of concretes are properties of great importance in civil engineering problems. To this day, despite the relevance of the subject, concretes are still designed based on charts and empirical formulae. This scenario is even more imprecise for lightweight aggregate concretes (LWAC), which contain less design methodologies and case studies available in the literature. In this sense, the present work presents a numerical simulation for predicting the properties of LWAC’s specimens using the Finite Element Method. The material was considered as biphasic, comprising lightweight aggregates and the enveloping mortar. Each phase was modelled with its own compressive strength, tensile strength and Young’s modulus. The achieved numerical results for fc and Ec were compared with their experimental counterparts, obtained from the literature. In total, 48 concrete formulations were assessed. Numerical results showed fair agreement with the experimental data. In general, the Mean Absolute Percentage Error (MAPE) was lower for the shale aggregates for both Young's modulus (1.75% versus 4.21% of expanded clay) and compressive strength (4.19% versus 9.89% of expanded clay). No clear trend of error was identified in relation to the aggregate proportion or to the mortar types, in which the MAPE varied from 2.36% to 8.13%. In conclusion, the simplification to spherical aggregates has shown satisfactory results, as has the adoption of a 2D model, which require less computational resources. Results encourage further applications with more complex geometrical aspects to improve the mix design and safety of LWAC.

Fine solid wastes as a resource-conserving filler and their influence on the performance of asphalt materials

Abstract Currently, the reuse of fine solid wastes (FSW) as cleaner production, instead of raw material, helps in improving road performance, easing excavation of virgin material and reducing environmental pollution. Nevertheless, concerns over poorer pavement performance caused by the addition of FSW have hindered the prevalent reusing of FSW in pavement engineering. Therefore, seven types of filler with five filler-binder volume ratios (FBv) were selected to prepare thirty-five types of asphalt mortar, in this study. The relationships among diversities of physical and chemical indexes of seven types of filler were firstly analyzed. Then, stripping test was applied to investigate the moisture sensitivity of asphalt mortar. After that, the effect of FBv and Rigden void of filler on the performance of asphalt mortar was evaluated. Moreover, the mechanism for the impact of FSW on the property of asphalt materials was comprehensively studied based on the rheological, mechanical and microscopic performances. Additionally, environmental impact of filler and mixture in the early stage was evaluated. In conclusion, the moisture damage mechanism of mixture in terms of surface free energy theory and asphalt mortar system was revealed, which indicated that the effect of filler on binder can be classified into four mechanisms; “physical hardening”, “chemical bonding”, “moisture instability” and “polarity enhancement”.

Dimensional analysis and calibration of a power model for compressive strength of solid-clay-brick masonry

In the present work, the power model adopted to predict compressive strength of masonry as a function of brick and mortar strengths was studied by means of Dimensional Analysis, identifying the main dimensionless groups ruling the problem. The approach was applied on a dataset of solid-clay-brick masonry tests collected from the literature. Data were represented in a novel way that permitted to display the importance of the main dimensionless parameters. The dataset was filtered distinguishing these parameters and used to propose a new calibration of the power model considering mortar type and geometry of the specimens. Results show an interesting improvement in terms of indicators of regression quality with respect to the power models proposed in the literature. Both Dimensional Analysis and regressions confirm that the power models are specific for the type of specimens, i.e. dimensionless parameters, used for their calibration and direct comparisons among them should be done with great caution.

Pore Structure Degradation of Different Cement Mortars Exposed to Sulphuric Acid

Acid attack causes the deterioration of construction material surfaces. The objective of this study was to investigate the degradation of different types of cement mortar in terms of variations in pore size distribution obtained by mercury intrusion porosimetry (MIP), mass loss, and compressive strength. The mortars were manufactured with nanosilica, zinc stearate, and an ethyl silicate coating. After curing (28 days), the samples were subjected to acid exposure for 90 days, immersed ina solution (3% w/w) of sulphuric acid (H2SO4). The results indicate that the mortars showed a more refined microstructure, with a higher proportion of smaller pores (<100 nm) compared to the control mortar. The 28-day and 90-day compressive strength variations of mortars were also determined by observing pronounced reduction due to the appearance of expansive compounds responsible for microcracking.

Cellulose fiber as bacteria-carrier in mortar: Self-healing quantification using UPV

Crack formation due to shrinkage or tensile forces is a major weakness of cementitious materials. To overcome this problem, in this study a self-healing mortar is produced using mineral producing alkaliphilic bacteria. Authors have used bacilius subtilis strain 168 type of bacteria to improve the ability of cementitious mortar to heal any formed cracks without any external intervention. Bacteria-based self-healing concrete/mortar needs bacteria-carriers to protect bacteria in a dense matrix to maintain the mineral-forming capacity of bacteria. However, the currently used bacteria-carriers are not always suitable for concrete because of their complex procedures or high cost. To develop a more suitable bacteria-carrier, in this paper feasibility of alkali treated micro cellulose fiber as a novel bacteria-carrier for self-healing mortar is investigated. Two types of bacterial mortar by using cellulose fiber as a bacteria-carrier were prepared. For one type, nutrients were added inside the mortar mix, while for the other, nutrients were added into the curing water. The crack healing efficiency of bacterial mortars was investigated using image analysis and ultrasonic pulse velocity (UPV) test and compared with unreinforced and control cellulose fiber mortars. Research shows that self-healing mortar using cellulose fiber as a bacteria-carrier result in maximum self-healing as compared to other mixes, 8.23% more than control samples, pre-cracked at 28 days with damaged degree between 0.1 to 0.2. At the dosage investigated, addition of cellulose fiber resulted in a decrease in compressive strength. It was observed that cellulose fiber increase the availability of bacteria in cracked region by acting as a bridge across the crack. Furthermore, cellulose fibers have a low cost and simplest method of immobilizing bacteria when compared with other bacteria carriers.

Age effect on the mechanical properties of natural hydraulic and aerial lime mortars

This paper focuses on the advanced mechanical characterization of natural hydraulic and aerial lime mortars presenting a lime/aggregate ratio of 1:3 and a water/lime ratio of 0.9. Seven properties, such as density, flexural, compressive and splitting tensile strengths, fracture energy, elastic modulus from prisms and carbonation depth by means of the phenolphthalein method, were measured at different moments. The results show that the greatest increase in the mechanical properties of both mortars occurs up to the first 56 days. This increase ranges between 60% and 90% of their corresponding value at an age of 448 days depending on the mechanical property and type of mortar. Between day 56 and day 224, there is a more moderate, but progressive evolution. However, after day 224, the evolution of the mechanical properties in light of their mean value, is very slow for the aerial lime mortar and shows a slight increase for the natural hydraulic mortar. Furthermore, various empirical equations of such behavior over time are proposed for both mortars.

Nano-TiO2 in Hydraulic Lime–Metakaolin Mortars for Restoration Projects: Physicochemical and Mechanical Assessment

In recent years, lime mortars mixed with artificial or natural pozzolans are commonly used in restoration applications. The aim of this work is the assessment of carbonation, pozzolanic reaction, setting time, and mechanical properties of metakaolin–lime mortars mixed with crystalline nano-titania (nT) as additive. The studied mortars consist of hydrated lime and metakaolin in 60/40 ratio (wt%) and fine aggregates of either carbonate or silicate sand. The concentration of the nano-titania is equal to 6 (wt%) of the binder. For comparison purposes, three types of mortars and pastes are designed: Without the addition of nano-titania, with nT activated or not under UV irradiation. The evaluation of the carbonation and pozzolanic reaction over a 1.5-year curing period is carried out through thermal analysis (DTA/TG), infrared spectroscopy (FTIR) and X-ray diffraction analysis (XRD). The uniaxial compression and the three-point bending tests at 28 days, 3 months, and 6 months were carried out to evaluate mechanical properties. The addition of activated nano-titania, due to an increased photocatalytic activity, accelerated the setting of the mortars, improving at the same time the mechanical properties. The plastic behavior of the lime–metakaolin mortars with activated nT was attributed to the evolution of carbonation and pozzolanic reaction.

Investigation of historical mortars from Belém do Pará, Northern Brazil

Belém do Pará, founded in 1616, still has layers of lime mortar on its historical buildings, which recurrently need restorative interventions. Intervention strategies need to include the use of building materials compatible with the original materials and, therefore, a good characterization of the original composition is necessary for the restoration of historical monuments. Thus, the main objective of this paper is the chemical, physical, and mineralogical characterization of historical mortars in Belém do Pará from the 18th and 19th centuries, as well as to evaluate their physical and mechanical properties. The results obtained showed the type of mortars used in different buildings and their main components, as well as the mortars behavior that helped the durability of the historic masonries. The conclusions leaded to useful information for seculars mortars restoration of northern Brazil.

Compressive Tests of Historical Brick Masonry – Case Study of the Archduke Rudolf Caserns Buildings in Cracow

ABSTRACT This paper presents an experimental study on masonry columns and core samples extracted from the structures of buildings erected in a historical caserns complex in Cracow. The samples were cut out from masonry made of clay bricks and various types of mortars. Samples from masonry with low-strength lime mortars were also extracted. The original historical masonry materials were tested under compression. The strength test results were compared with mechanical characteristics of masonry obtained from formulas given in Eurocode 6. Experimental formulas for determining the compressive strength and modulus of elasticity of historical masonry were proposed. The paper also discusses the tests on masonry core samples. This minor destructive technique is useful for historical buildings where cutting out large dimension samples are not allowed. The methods of preparation of cylindrical samples and interpretation of tests results are discussed.

Influence of the backfill parameters in distinct element modelling of a backfill masonry arch bridge through the PFC2D software

ABSTRACT This paper presents an investigation on how to model a backfill masonry arch bridge using the discrete element method (DEM). The PFC2D software is used for this purpose. A certain backfill masonry arch bridge is modelled, with different types of fill, mortar and voussoir materials. A biaxial test has been programmed using ‘FISH’ code to obtain the micro-parameters used in the model so that they match the macro-parameters obtained from a real biaxial test. The arch is loaded until its collapse in three different load cases. Further discussion on the influence of the backfill parameters is presented as well as a sensitivity analysis for the arch bridge.

Microstructure and bonding behavior of fiber-mortar interface in fiber-reinforced concrete

The interfacial properties between fiber and matrix play a critical role in the overall mechanical responses of composite materials. In this paper, the glass fiber-mortar interfacial microstructure in fiber reinforced concrete (FRC) is visualized and characterized using X-ray microscopy. Additionally, three types of fiber-mortar interface (glass fiber, high modulus polyvinyl alcohol (PVA) fiber, and basalt fiber) are analyzed by scanning electron microscopy and energy dispersive X-ray spectroscopy. The results revealed a lot of microcracks along with the glass fiber-mortar interface; moreover, the hydration product of the glass/PVA/basalt fiber-mortar interface was much lower than that of the mortar matrix. Because microcracks or lower hydration product have such a negative effect on the interfacial bonding between fiber and mortar, the objective of this paper was to provide an analysis of this problem through extensive testing of their bonding properties. Specimens made of three types of fiber were tested along with three different mortar types under tensile stress and a combined stress state to investigate the interfacial bond properties between fiber and mortar. Results show that both of the tensile and shear bond strength of the interface were not only improved by stronger mortar matrix, but also significantly affected by fiber type. Furthermore, when the interface failed by slipping along the interfacial area, the interface showed an increasing shear bond strength with the increase of compressive stress. This was not the case when failure was due to the crushing of mortar. Finally, the FRC splitting tensile strength was tested to demonstrate the bonding mechanism effects on the FRC mechanical properties.

Construction and demolition waste as partial cement replacement

In recent years several studies have been carried out using waste from various industries to partially replace cement in concrete. In addition to improving concrete durability, the use of these waste materials also contributes to reducing emissions, mainly carbon dioxide, and to saving resources. In this study, the applicability of finely ground construction and demolition waste (CDWg) in concrete as a partial substitute for Portland cement was evaluated and the effects on durability were assessed. Mortars and pastes with cement replacements of 0%, 5% (CDWg5) and 10% (CDWg10) were produced. The different mortar types were tested to ascertain their 7, 28 and 90 d strengths and durability-related properties, including capillary absorption, chloride diffusion, accelerated carbonation, resistance to alkali–silica reaction (ASR) and sulfate attack. Mortar containing CDWg performed better than the control only with regard to expansion due to ASR. In the other tests, mortar containing CDWg did not attain the performance of the control specimens. However, for the CDWg5 mortar, performance losses were not significant, indicating that this particular waste at this dosage may be used to partially replace Portland cement. A replacement of 10% could be considered in concretes with lower levels of performance requirements.

Customers’ Switching Behaviour in the Banking Industry in Cape Coast Metropolis, Ghana

Deregulation, intense competition and the banking sector crises in Ghana has led to increased customer switching. It has, therefore, become crucial not just to attract every potential customer, but also to develop strategies aimed at maintaining the existing customers. This study sought to investigate the factors that affect the switching behaviour of customers in the banking industry in Ghana. Data for this study was obtained using self-administered questionnaires from 500 bank customers. A descriptive cross-sectional survey was adopted for the study. Binary logistic regression technique was used to analyse the data. The results revealed a significant relationship between customers’ switching behaviour and the variables of interest, including, price, advertising, reputation, distance to bank location, switching cost and innovative products offered by banks. The study recommends that banks should embark on effective advertising campaign about the benefits of their products and improve upon their reputation. Banks should invest in technology and reduce their investment in bricks and mortar type of banking structures. Keywords : Banking, Customer Switching Behaviour, Ghana DOI : 10.7176/JMCR/61-01 Publication date :October 31 st 2019

Effects of Rubber Size on the Cracking Resistance of Rubberized Mortars.

This study investigated the cracking resistance of rubberized cement-based mortars. Three rubber particle sizes were used: Rubber A (major particle size 2–4 mm), Rubber B (major particle size 1–3 mm), and Rubber C (major particle size 0–2 mm). Traditional restrained ring shrinkage test (RRST), new restrained squared eccentric ring shrinkage test (RSERST), mechanical test, and scanning electron microscopy test were conducted. Results showed that the cracking inhibitory effect of Rubber B was the highest among the three rubber particle sizes. SEM results revealed that the particle size of the rubber does not have much effect on the ITZ (interfacial transition zone) position of rubber and cement paste. For the strength differences of the three types of rubberized mortar, it is mainly because the specific surface area increased as the rubber size decreased, which lead to more ITZ positions and pore structures. Our study verified that RSERST can predict the cracking position and shorten the test period. Compared with RRST, RSERST can also increase the restriction degree. is defined as the intensification factor of RSERST restriction degree. The average intensification factor is .

A model to predict ammonia emission using a modified genetic artificial neural network: Analyzing cement mixed with fly ash from a coal-fired power plant

Selective catalytic reduction (SCR) and selected non-catalytic reduction (SNCR) use ammonia as a catalyst for removing nitrogen oxides in power plants. However, unreacted ammonia in the flue gas denitrification system reacts chemically with SO3 and is adsorbed on the coal fly ash. Unfortunately, fly ash is commonly mixed with concrete because of its technological and economic benefits, without consideration of secondary environmental contamination. We measured the ammonia emissions from different types of fly ash mortar and found they have a strong correlation with the mixing ratio of fly ash, the mortar age, and the size. In order to find out this correlation and thus predict the ammonia concentration under different conditions, we constructed artificial neural network (ANN) models. The comparison results show that the ANN model initialized with the genetic ANN (GANN) algorithm has the smallest root-mean-square error (RMSE) between given and predicted outputs.

General Status of Food Cheats in Turkey

Objective: Nutrition has an important place in the preservation of public health, raising the living standards and development of the country's economy. In order to ensure food safety and quality, it has determined the principles and procedures regarding the inspection and control services of the materials and materials in contact with food and food and the minimum technical and hygienic conditions and responsibilities of the food enterprises, and has made some recognitions. This study was carried out in order to reveal the lists of the products which are finalized in the official website of the Ministry in accordance with the Article 8 of the By-Law on the Official Control of Food and Feed. Method: Qualitative research method was adopted in this study which examined the food lists which were confirmed by the Ministry of Food, Agriculture and Livestock between 2013-2018. The data were converted to statistical data by using the content analysis method. Results: As a result of the content analysis of the lists between 2013-2018, it was determined that a total of 1073 party products were subjected to imitation and adulteration and these products belonged to 815 enterprises. Most of the products made to pretend and adulterated cheese (161 pieces), olive oil (160 pieces), sunflower oil (96 pieces), sausage varieties (91 pieces), yogurt (85 pcs), ready-made dumplings (80 pieces) and honey varieties (65 pieces), reinforcing foods (63 pieces), ready mortar types (51 pieces) and butter varieties (41 pieces). Discussion and Conclusion: As the awareness of the modern society's feeding patterns, the negative effects of future generations, children and health on the whole, the societies try to learn more about the foods they consume. To reach the most transparent information about foods in the globalized world is becoming the most natural right of being human and law. However, from the start of the commercial production of food, it is known that foodstuffs are exposed to some tricks such as imitation and adulteration from the field to the fork and various arrangements (laws etc.) are made in order to combat these situations. Considering that 1073 party products were imitated and adulterated between 2013-2018, the fact that these products were produced by imitation and adulteration, how long it was produced, how long it was left in the market, how much of it was sold and consumed, prevented the question of the extent of the situation. Keywords: Food safety, imitation, adulteration, food regulation DOI: 10.7176/JSTR/5-9-07

Specimen size effect on the durability indexes determination for cement-based materials

In this project is required to determine if there is any result variation in durability indexes due to size effect in sizes of mortar specimens. Cubes 5 x 5 cm, 5 x 10 cm and 10 x 20 cm cylinders for each mortar type were considered. It was found that in certain indexes (WER, TVC, and CS) results did not depend on specimen´s geometry. Nonetheless, UPV index result presented differences up to 17.5 % between the cubes and the 10 x 20 cm cylinders. εeff index result showed an interesting difference between the cubes and the 5 x 10 cm cylinders used in full length. Therefore, it is recommended to restrict the height of the specimen to a standard value

Structural Behavior of Small-Scale Masonry Panel with Fiber Reinforced Mortar under Compressive Load

The use of fiber reinforced mortar for structural retrofitting/new construction of masonry structures has become increasingly popular in the last years. A preliminary study on the mechanical performances under compression of masonry panels is performed by selecting three different mortar types. The panels were composed of mortar and clay bricks; the mortars adopted are the following: i) commercial type mortar, ii) traditional mortar and iii) traditional mortar with the addition of a cellulose-based industrial non-hazardous waste. In particular, the study proposes the use of deink paper sludge as mortar filler as an example of sustainable end-of-life reuse. Using the collected experimental results involving the mortars and clay brick form a regression analysis on compressive strengths was performed in order to evaluate the influence of the deink paper sludge on the compressive behavior of the panel.