Use Of Mortar Research Articles

Waste of Civil Construction for Use in Mortar and Production of Structural Concrete

Civil construction is a sector of extreme impact on the Brazilian economy, both in terms of jobs as well as consumption of raw material and waste generation. Civil construction waste (CCW) represents a large part of the total mass of municipal solid waste in a medium and large city. An alternative to diminish these released wastes is to reuse them. In this work, a study was carried out using CCW both to produce concrete with sand substitution and as a small aggregate for use in mortar. The compression strength of structural concrete and mortar, with total and partial replacement of sand, was analyzed. In addition, the consistency of mortar with the replacing was also studied. The results of the compression test indicate superior quality for concretes (75wt% CCW) and mortar with CCW incorporation. The required amount of water for good workability in the modified mortar is 310 g, against 270 g for the reference mortar.

Analysis of deformability modulus by linear and nonlinear elastic methods in ceramic structural masonry and mortars

Abstract There are studies analyzing the parameters of structural masonry strength, however few are performed evaluating the interference of the mortar in the deformability parameters. The objective of this study was to verify the theories of elasticity (Hooke’s linear model and nonlinear models by Ghosh, Duffing, and Martin, Roth, and Stiehler) applied to structural masonry. Ceramic blocks were pressed and fired at 890 ºC and mortars prepared with the proportion 1:1:5:0.5:2 of cement: hydrated lime: sand: PVA binder: water. The materials were tested in compression individually and in prisms with and without the use of mortars. The results obtained with the linear elastic analysis were incoherent since the deformability modulus obtained for the mortar prisms was higher than those without mortar. Performing the analysis by nonlinear theories, it was found that the results obtained were more coherent, mainly by Duffing’s theory that uses one parameter for stiffness and another for damping of the material.

Verification of the application potential of the mathematical models of lyse, abrams and molinari in mortars based on cement and lime

Cementitious materials have relevant applications related to the civil construction sector, such as concretes and mortars. However much of the existing technological research favors concrete, which makes mortar a still deficient material for research. The water / cement ratio is an extensively investigated parameter for concretes, however, it is still very little studied in mortar. The Abrams, Lyse and Molinari equations, for example, are consecrated in their application in concrete, but not yet evaluated for mortars, being a scientific gap. The objective of this work was to evaluate for the first time the effect of the water / cement ratio in mortars, using three different mixtures, in proportions of [1: 1: 6], [1: 2: 9] and [1: 0: 3] for cement: lime: sand combined with two different types of Portland cements. Based on these relationships the aforementioned equations investigating mortars were characterized. Mass consistency tests as well as mechanical resistance to compression and flexion test at 14 and 28 days as well as water absorption by capillarity and by immersion together with density measured in the hardened state were performed to verify the Abrams, Lyse and Molinari laws, and their possible validation for use in mortars. The results prove that the water / cement ratio considerably affects the evaluated technological properties and that the Abrams and Lyse equations are viable for application in mortars, just as they are applied to concretes. As for the Molinari equation, it requires mathematical modification, and the fresh mortars density.

Compositional and textural characterization of historical bedding mortars from rubble stone masonries: Contribution for the design of compatible repair mortars

The present research addresses the compositional and textural properties of bedding mortars from rubble stone masonries of a historic construction, built between 13th and 17th centuries and during different constructive periods (National Palace of Sintra, Portugal). The characterization of mortars established the basis for the formulation of compatible repair mortars. The mortars revealed similar composition and depended on the raw material locally available (calcitic binder and aggregates of granitic nature), whereas the textural features (b:a and aggregate gradation) varied significantly according to mortar use (interior/exterior walls; interior/exterior leaf of exterior walls). Statistical analysis on textural data allowed to propose different repair mortar formulations according to their use; one for interior walls (b:a ≈ 1:2) and two for exterior walls (b:a ≈ 1:3 and b:a ≈ 1:4).Besides, the research found consistent correlations between mortars’ characteristics and the historical background of the monument although further analyses are required for a definitive link between masonries materials and the constructive periods.

Sustainable mortar mix using recycled fines obtained from construction and demolition waste

Rivers are over exploited for natural sand extraction and production of cement has triggered global warming. For sustainable development a study has been conducted to use construction and demolition waste (CD-W) in cement-sand mortar. In the present study, crushed CD-W in the form of recycled concrete fine aggregate (RCFA) and recycled concrete powder (RCP) has been planned to be used in cement-sand mortar as replacement of natural standard sand (NSS) and cement, respectively. The effects of partial replacement of NSS and cement with RCFA and RCP on compressive strength and split tensile strength after 7th and 28th day of curing have been evaluated. Outcomes of elevating replacements of cement and sand in mortar have been found to be decreasing gradually, but falls above the minimum limit of 7.5 N/mm2 as established by IS: 2250 (1981) for use of mortar in structural applications. Therefore, the study concludes the valid potential of RCFA to be utilized up to 100% percent and RCP up to 20% as partial replacement of natural sand and cement, respectively in mortar production.

Cristina Montana Pușcaș, Iosif Vasile Ferencz, Ciprian Cosmin Stremțan, Tudor Tămaș, Adrian Căsălean, The amazing architecture of the Dacians. Few thoughts concerning the use of mortars based on new analyses

In 2016, while carrying out a campaign on a Dacian “tower-house” type structure identified in earlier years on the Cetățuie Hill in Ardeu, an atypical material was noticed on the inferior surface of a stone block sitting perpendic¬ular on the revetment. Its appearance, of different colour and texture compared to the stone block it was attached to, led us to immediately assume it could be mortar. Based on this working hypothesis a series of questions were formulat¬ed, with the purpose of extracting as much valuable information as possible from the sample. Powder X-ray diffraction and petrographic investigations were carried out in order to answer these questions.

Nonlinear finite element analysis of traditional flexural strengthening using betung bamboo (Dendrocalamus asper) on concrete beams

Structural failure, which can be caused by design miscalculation or changes in the building’s function, can be dangerous if left untreated. Consequently, structural strengthening is done by providing steel plates, fiber-reinforced-polymer, or in the traditional way using bamboo fibers. In this study, a numerical calculation for bamboo strengthening using the FEM method is conducted. Bamboo strengthening was installed on concrete beams and attached using mortar. The analysis was carried out with ATENA software dealing with beam specimens, namely Control Beam (BC) and Bamboo-strengthened Beam using M13 and M20 mortar (BB13 and BB20). The materials used are CC3DNonLinCementitious2 and CCD3DBiLinearSteelVonMises for concrete and bamboo, respectively. The concrete and mortar use the fracture concept of a uniaxial stress-strain law and the constitutive model of the bamboo is based on a linear stress-strain law. The results of comparing the numerical and experimental results for the load-carrying capacity ratio are 0.96, 0.90, 0.77 for BC, BB13, and BB20, respectively. The crack pattern of the specimens shows that collapse is by flexural cracking starting from the mid-span. This is in accordance with previous laboratory results. In conclusion, the analyses using ATENA program and experimental methods show the appropriate results.

Formation of Friedel’s salt using steel slag and potash mine brine water

The increasing depth and widening scale of potash mines are suggestive of the use of mortars with greater homogeneity and fluidity properties for mine backfills. Results of the experimental investigations discussed herein indicated that the flow property and the later strength of mortars can both be satisfied through the utilization of steel slag (SS) as a binder in potash mines. Paste samples were evaluated in terms of the hydration mechanism for the mixture of brine water (liquid waste from potash mines) and SS, and were found to achieve a compressive strength of 10 and 15 MPa after 28 and 60 curing days, respectively. An analysis carried out for the microstructure of the pastes revealed C–S–H gels and Friedel’s salt being the main hydration products in the system, in which active interpenetration between the substances contributes to the enhancement of the paste’s strength. Impure ions in the system can be fixed to improve the stability of the filler through the formation of Friedel’s salt. Overall, the findings of the present study confirmed that SS exhibits a latent hydraulic behavior and can be used as a binder in mortars for long-distance transportation in potash mines.

Phase Change Materials for Energy Efficiency in Buildings and Their Use in Mortars.

The construction industry is responsible for consuming large amounts of energy. The development of new materials with the purpose of increasing the thermal efficiency of buildings is, therefore, becoming, imperative. Thus, during the last decades, integration of Phase Change Materials (PCMs) into buildings has gained interest. Such materials can reduce the temperature variations, leading to an improvement in human comfort and decreasing at the same time the energy consumption of buildings, due to their capability to absorb and release energy from/in the environment. In the present paper, recent experimental studies dealing with mortars or concrete-containing PCMs, used as passive building systems, have been examined. This review is mainly aimed at providing information on the currently investigated materials and the employed methodologies for their manufacture, as well as at summarizing the results achieved so far on this subject.

Study of historical value mortars

The rehabilitation of buildings, or historic landmarks, has gained in importance over the years. It is increasingly important to safeguard the cultural identity and history of a country. In this research the mortars of the Roman city of Conimbriga were studied, being one of the oldest archaeological cities in Portugal. Conímbriga has its origin in a Celtic Castro of the tribe of the Conii, at the end of the Iron Age. It was occupied by the Romans from 139 BC. It was under the Emperor Augustus Empire, in the second century AD, that the city achieved its splendor, having then been built public baths and a Forum. With the decline of the Empire, in the late fourth century, a monumental defensive wall was erected, which did not prevent the assault of the city by the Suevi, in 468, and the consequent decline of the city. Large excavations carried out throughout the 20th century revealed a valuable and complex set of buildings, including thermal baths, an aqueduct that runs more than 3,400 meters from the source, and remains of a Christian basilica, probably from the 6th century. In this type of rehabilitation works the use of mortars was predominant, hence the importance of their study to know how they behave. In order for a rehabilitation intervention to be successful it is necessary to know the existing support in place to guarantee the compatibility of the materials. It was necessary to go “in situ” to collect the samples with the proper authorization of the Museum of Conimbriga. These mortar samples were analyzed and characterized by scanning electron microscopy (SEM) for further analysis. The composition of the samples will allow to adjust dosages and to choose a restoration mortar, as close as possible, to the one that was collected in order to preserve the maximum historical identity of the place.

Determination of Optimum Hot-Water Temperatures for PCM Radiant Floor-Heating Systems Based on the Wet Construction Method

Owing to use of mortar, which demonstrates low heat storage and discharge performance, conventional radiant floor-heating systems, based on the wet construction method and hot-water circulation, consume large amounts of energy. This study proposes a new type of radiant floor-heating system that is capable of reducing energy consumption via use of the latent heat of a phase change material (PCM), whereby the phase change, which occurs within, is induced by the thermal energy supplied by hot water. Simulation analyses revealed that hot-water supply temperatures, required to maintain the floor-surface and indoor-air temperatures at the set point using PCM latent heat, were in the range 40–41 °C. At supply water temperatures measuring less than 39 °C or exceeding 42 °C, the latent-heat effect of the phase change of the PCM tended to fail, and the corresponding floor-surface temperature assumed a value different from that corresponding to the set point. By contrast, supply temperatures in the range 40–41 °C resulted in return temperatures measuring approximately 27.4–27.5 °C, which in turn corresponded to an indoor air temperature of 21.6–22.6 °C that was stably maintained within ±0.6 °C of the 22 °C set-point temperature.

System of Elements for Buildings Erection by Dry Method

The volume small-sized elements for the erection of bearing and enclosing walls of buildings are described. A feature of the proposed products is the possibility of their laying in a dry way without the use of mortars. The variants of the arrangement of the elements are given in the case of abutting the transverse walls, as well as in the corners of the building.

Recycling paper industry effluent sludge for use in mortars: A sustainability perspective

Abstract The paper and cellulose manufacturing industry generates significant quantities of waste, including an extremely humid sludge, which is considered to be an effluent with high environmental liability for the manufacturer. Studies have shown that this waste sludge may be utilized in construction material, such as mortar for fixing blocks, as well as for ceiling and wall coatings that use ceramic masonry as a sealant. The recycling of pulp and paper industry waste sludge has important environmental benefits, by preventing soil and water pollution caused by inadequate disposal and by reducing the depletion of natural resources, such as lime, used in cementitious materials. This study analyzed the sustainability of incorporating such waste into cement-based mortars. Tests were conducted replacing lime, one of the most expensive mortar components with high environmental impact, with waste sludge in contents of 5%, 10%, 15%, and 20%. Analysis was then performed on the samples to assess the primary technical characteristics of these incorporated mortars, such as the consistency index, heat of hydration, content of incorporated air, water retention, mechanical strength and the capillarity coefficient. The results were compared with the results of the characterization tests that were performed on the waste material. The results showed that for use in wall and ceiling mortar coatings, the level of incorporation should not exceed 10%, because higher levels yield lower values of mechanical strength resistance, incompatible with market requirements. This result is probably due to the low heat of hydration of the waste material which generates slower reactions. On the other hand, higher levels of waste material content, above 10%, are appropriate convenient for mortar used to fill small repairs in masonry that do not require control of properties.

Possible Use of Diatomite and Pumice-Amended Mortar and Plaster in Agricultural Structures

This study was conducted to investigate the potential use of diatomite (a natural pozzolana) and pumice in plasters and mortars to be used in agricultural buildings. Compacted and loose unit weights, specific weight, water absorption, organic matter content, abrasion resistance of aggregate (sand and pumice) and pozzolana were investigated and materials were found to comply with the relevant standards. Test results on fresh (unit weight and slum test) and hardened (unit weight, capillary water absorption, total water absorption, bending and compressive strength, vapor diffusion test) mortar samples revealed that pumice and diatomite could be used in agricultural structures. Diatomite and pumice should be heat-treated and grounded before to use in mortars. In plasters to be made with abundant pumice and diatomite sources, high water holding capacity of the materials should be taken into consideration and further researches should be carried out about their compliance with the other materials.

Using Mortar Mixing Pump for Magnesia Mortars Preparing and Transporting

The article is devoted to the problem of preparation and transportation of magnesia mortars with the help of screw mortar mixing pumps. The urgency of the wide use of mortars on magnesia binders (Sorel’s cement) in construction is substantiated due to their high characteristics: strength, hardening speed, wear resistance, possibility of using organic and mineral aggregates, ecological purity and economic efficiency. The necessity for the development of a technique for calculating the main parameters of a mortar mixing pump for its application in the technology of preparation and transportation of magnesia mortars is demonstrated. The analysis of various types of modern mortar mixing pumps is given. The conclusions are drawn about the advantages and disadvantages of standard schemes. The description of the experiment for determination of the productivity of a mortar mixing pump is described depending on the plasticity (mobility) of the used magnesia mortar. The graph and description of the mathematical dependency of the productivity of the mortar mixing pump on the magnesia mortar plasticity are given. On the basis of the obtained dependency, as well as the already known formulas given in the article, a new method is proposed for calculating the main parameters of the screw mortar mixing pump in preparation and transportation of magnesia mortar: productivity, feed range, supply pressure, drive power.

Pemanfaatan Bekas Adukan Mortar pada Pratikum Batu (Masonry) untuk Paving Block

Stone Construction Laboratory is one of the existing courses in the Department of Civil Engineering Polytechnic State of Padang. Students are required to practice firsthand the theories about stone construction that have been studied. Stone work or often called masonry is wall or brick installation work for floor, wall, or fence. In practicum stone, the material used is artificial stone like brick and can also natural stone by using an adhesive substance usually known by the name of spesi or mortar.Mortar or spesi is one of the building materials that serves to glue the pairs of bricks, brick, stucco and so on. Mortars consist of sand, cement and water. In a stone work practicum where the work is not permanent (unloading pairs) then the cement material is replaced by lime which is a temporary binder. So far, the rest of the mortar use for the stone practicum is just thrown away because it cannot be used anymore, therefore it takes alternative utilization of the former mortar, for that the author tries to research by using it to make paving blocks. Paving blocks or concrete bricks for floors are a component of building material made from a mixture of hydraulic cement or the like, aggregates and water with or without other additives which do not reduce the quality of the paving blockThe study used comparison between paving block with mixed composition of mortar, cement and water mixture and paving block with standard mixture composition ie cement, sand and water. Paving is made by pressing using hydraulic press machine with a compressive strength of 25 kg and compressive strength testing with Universal Testing Machine.Based on the results of the research, it was found that the paving block from the utilization of mortar has a compressive strength higher than the standard paving block. At the age of 14 days, the compressive strength of the paving block from the utilization of mortar used has a compressive strength of 76.14 kg

Effectiveness of new natural fibers on damage-mechanical performance of mortar

Addition of fibers to cement-based materials improve tensile and flexural strength, fracture toughness, abrasion resistance, delay cracking, and reduce crack widths. Natural fibers have recently become more popular in the construction materials community. This investigation addresses the characterization of a new animal fiber (pig hair), a massive food-industry waste worldwide, and its use in mortars. Morphological, physical and mechanical properties of pig hair are determined in order to be used as reinforcement in mortars. A sensitivity analysis on the volumes of fiber in mortars is developed. The results from this investigation showed that reinforced mortars significantly improve impact strength, abrasion resistance, plastic shrinkage cracking, age at cracking, and crack widths as fiber volume increases. Other properties such as compressive and flexural strength, density, porosity and modulus of elasticity of reinforced mortars are not significantly affected by the addition of pig hair.

Fire performance of non-load-bearing light-gauge slotted steel stud walls

Experimental and numerical studies on the performance of light-gauge slotted steel stud walls subjected to fire are presented in this paper. Four full-scale light-gauge slotted steel stud walls were tested under the ISO-834 standard fire loading. Temperatures at the location of exposed surface, unexposed surface, and cross section of steel studs were measured. Spalling of the heated gypsum board during testing was investigated. The major factors affecting the behavior of this type of wall, including the height of the web, layers of gypsum boards and use of mortar on unexposed surface, were studied.Based on the test results, a three-dimensional FE model of the light-gauge slotted steel stud wall was developed using ABAQUS to analyze its fire performance. The model was validated against experiments in this study and other related test data. The FE model was employed to conduct further parametric studies. Parameters include the spalling time of heated gypsum boards, the height of the web, rows of slots, and layers of gypsum boards. The effects of these key factors on the temperatures of the exposed surface, unexposed surface and studs are discussed.

Mechanical characterization of different FRCM systems for structural reinforcement

This experimental work aims to evaluate the strengthening effectiveness as well as the mechanical behavior of different Fiber Reinforced Cementitious Matrix (FRCM) systems. The use of mortars with different strength classes coupled with fabrics made of carbon, basalt or PBO fibers has been investigated. In the case of both carbon and basalt fibers a polymer coating was also applied, in order to check the likely improved adhesion with mortars. These composite systems have been characterized by means of tensile and double shear bond tests. Tensile tests have been performed with clevis grips (AC434.13), by changing the contact length of the metal tabs used to grip the ends of the specimen, in order to understand the influence of the latter on the FRCM tensile characterization. Different bond lengths were analysed in double shear bond tests, using clay brick walls as substrate, so as to evaluate the influence of the bond length depending on the reinforcement system used. Carbon and PBO were also coupled with high-performance mortar so as to understand the effect of using high performance cementitious mortar as matrix for composite systems. Finally, FRCM performance and failure modes when reinforced with multiple carbon fabric plies have been investigated.

Reclaimed asphalt binders and mortars fatigue behaviour

Fatigue cracking is one of the most important failure mechanisms occurring in asphalt pavements, especially when mixtures incorporate considerable amount of rReclaimed asphalt pavement (RAP). In fact, aged binders contained in RAP generally make asphalt more brittle and specifically reduce fatigue resistance of the resulting asphalt mixtures. Binders and mortars play a key role in this phenomenon, considering fatigue cracking usually starts within these asphalt components. However, performance-related tests and specifications commonly regard binders and there are no sound methodologies allowing the use of mortars to predicting fatigue performance of asphalts containing RAP. For this reason, in this paper, fatigue resistance of extracted binders from high-RAP content mixtures and of RAP mortars (passing sieve with an opening size of 0.15 mm) were assessed and compared. Binders were extracted from asphalt mixtures manufactured with 30%, 60% RAP and rejuvenators. Mixtures recipes were then reproduced to manufacture mortars accordingly. Time sweep tests in stress-controlled mode were carried out on both materials (binders and mortars) and the resulting fatigue laws were compared. As a result, a strict correlation was obtained, leading to affirm fatigue-related properties of RAP mixture could be assessed by directly testing RAP mortars. This makes the recovery of RAP binders unnecessary. Moreover, a relationship between the two fatigue laws versus the percentage of fine particles in the mortar was found. This latter relationship allows determining the fatigue law of mortars corresponding to any percentage of fine particles and therefore corresponding to any percentage of RAP.