Traditional Mortars Research Articles

Influence of Glass Granular Class on the Compressive Strength of Glass-Sand Mortar

This study examines the effect of glass particle size and color on the compressive strength of mortars made from glass, sand, and cement. A range of water-to-cement (W/C) ratios was applied, and tests were conducted to measure density and compressive strength at both 2 and 7 days. The glass, available in green, brown, and white, was introduced as both fine and coarse particles. The findings reveal that incorporating glass significantly enhances compressive strength compared to traditional mortars without glass, regardless of its color. Brown glass, especially in its coarse form, exhibited the best mechanical performance. With a W/C ratio of 0.48, mortars containing coarse brown glass particles reached a peak compressive strength of 34.78 MPa, showing a relative increase of 134.52% compared to mortars without glass. Fine brown glass particles also demonstrated strong compressive strength, though lower than the coarse ones. The density analysis showed a positive correlation between density and compressive strength, suggesting that denser mortars perform better mechanically. The superior performance of coarse glass particles is likely due to their optimal granular distribution, which enhances the bonding between cement and glass particles, leading to greater overall strength. Keywords: Compressive strength – Particle size – Recycled glass – Mortar – Density

Optimizing Masonry Mortar: Experimental Insights into Physico-Mechanical Properties Using Recycled Aggregates and Natural Fibers

The European Green Deal establishes the efficient management of construction resources as one of its main lines of action. In this sense, the recovery of construction and demolition waste for its reincorporation into the manufacturing process of new sustainable materials has become necessary for the industry. This work deals with the physical and mechanical characterization of cement mortars made with recycled concrete aggregates and reinforced with natural fibers. The reinforcement fibers used (abaca, coconut, and toquilla) are more environmentally friendly compared to traditional synthetic reinforcements. The aim of this research is to analyze the main physico-mechanical properties of these sustainable cement mortars. The results show that mortars made with recycled sand have a lower density and better thermal performance than traditional mortars. In addition, with the incorporation of these natural fibers, the flexural strength of the mortars with recycled aggregate increased by up to 37.6%. Another advantage obtained from the incorporation of these natural fibers is the reduction in shrinkage in the masonry mortars during the drying process, giving them greater dimensional stability and making their behavior similar to that of traditional mortars. Thus, this work shows the potential application of masonry mortars produced under circular economy criteria and their application in the building sector.

A multi-performance comparison between lime, cementitious and alkali-activated TRM systems: Mechanical, environmental and energy perspectives

The combined need to propose new solutions for the structural reinforcement of existing buildings and for the reduction of CO2 emissions is leading to the development of more sustainable composite materials, such as those based on alkali-activated mortars (AAM). In this study, different formulations of AAM, based on metakaolin or fly ash, have been evaluated as possible matrices for Textile Reinforced Mortar (TRM) systems. Two different bidirectional textiles, made of AR glass or basalt fibers, were used as internal reinforcement. The physical-mechanical properties of TRM systems based on AAM were evaluated and compared with those of commercial systems with cementitious or lime-based matrices. Direct tensile tests on TRM coupons and shear bond tests on clay brick substrates were carried out. Then, their energy and environmental-related performance have been compared. Results showed that alkali-activated matrices can be very promising and eco-friendly alternative solutions to traditional mortars in TRM systems.

Limestone calcined clay cement (LC³) coating mortars as an energy-efficient option for construction

LC³ coating mortars have been developed by replacing 45 – 60 % of Portland cement with metakaolin and limestone (2:1) and using a 1:4.5 binder-to-sand ratio to create an energy-saving and environmentally friendly alternative. Their thermal conductivity was reduced by up to 51 %, and the thermal insulation was improved by up to 4 °C with just a 2 cm layer application compared to a mortar with 100 % cement. By increasing the water content by just 12 %, the consistency index of the mortar was maintained without using any additives. LC³ coating mortars with less cement and more sand still resemble traditional mortars, complying with all regulations.

Thermal behavior of Sicilian clay-based geopolymers

AbstractGeopolymers have been recently proposed for restoration of built heritage to substitute traditional mortars. Local materials and industrial wastes from the Italian region Sicily showed their potential as low-cost aluminosilicate sources for the preparation of geopolymers. Here, a set of Sicilian clays was studied by Thermogravimetry (TG) and Differential Scanning Calorimetry (DSC), and its mineralogical composition was evaluated by X-ray diffraction (XRD). The raw materials were used to prepare geopolymers by alkaline activation with or without the addition of silicate. The thermal degradation profile of the final materials was studied by TGA and compared with that of the precursors, and the energetics of dehydration were investigated by DSC. Two statistical analyses (made by Principal Component Analysis) were performed on the TG data of raw materials and geopolymers and on the TG data of geopolymers and their mineralogical composition, respectively. The last analysis in particular showed a correlation between the mineralogical composition of the materials and the samples' thermal properties. Additional studies of samples subject to accelerated aging by UV irradiation and exposure to acetic acid vapors highlighted the different effects of these two agents on the samples’ stability. Graphical abstract

Characterisation and Contextualisation of Mortars from the 19th and First Half of the 20th Centuries in Muharraq, Bahrain

ABSTRACT Within the context of the restoration projects at the buildings of the Pearling Path in Muharraq (World Heritage Site), interdisciplinary research has been conducted to determine the composition and historical context of the various mortars present in these historic structures. Some previous analyses carried out on historic mortars indicated a predominant use of gypsum, although lime was also frequently identified. However, the lack of details about the analysed samples did not allow estimating the possible composition of the local traditional mortars through their dating or location. To understand the use of historic mortars, an in-depth historical research and data analysis were conducted. This focused on the chronological sequencing of the buildings’ construction which was combined with petrographic analysis performed on a group of samples. Their selection was based on a pre-classification made according to the dating and the visible appearance of the mortars. The new data also enabled fresh conclusions on previously published studies. The obtained result is a mineralogical characterisation of the mortars used in Muharraq during the 19th and the first half of the 20th centuries, supported by historical data, including information about the provenance, the application criteria, and an explanation of changes in material trends. This information will assist heritage professionals in gaining a deeper understanding of buildings from this period in Bahrain, enriching the knowledge of materials used in the region. It will enable them to predict the composition of historic mortars based on dating, location, and visible physical features such as colour, type of aggregates, and binder-to-aggregate ratio.

Capillary Suction Properties of Mortar Made with Recycled Plastic Aggregates Elaborated from Waste Electrical and Electronic Equipment

It is possible to revalue the plastic fraction from WEEE using it as a recycled aggregate (RA) in cement mortars. However, this feasibility depends on elaborating a granular material via a core-shell strategy to stabilize the potential contaminants. The core is a plastic particle, and the shell is a cement, fillers, and activated carbon mixture. Due to the hydrophilic characteristics of the shell and the presence of interstitial sites generated by the use of the RA, it is necessary to study the wetting properties of these mortars. This article presents the results of capillary suction and contact angle studies of mortars made with RA having different shell compositions. The capillary suction of the latter is higher than in traditional mortars, which limits their use for structures exposed to water and environmental agents but opens the possibility of new uses in permeable concrete or for the manufacture of building components.

Bricks, Mud and Lime Mortars in Heritage Restoration: A case study

This paper is based upon an extensive eight-year experience in the restoration of monuments from the World Heritage Site Patan Darbar Square to Tripureshwor Mahadev Temple, Sattals, and Garden Area and the Sama Center, representing historically significant Malla, Shah and Rana period architectures respectively, after the Gorkha earthquake of 2015. These monuments date back from 6th to the 20th century. All structures employ a masonry system as the structural system. The main materials observed in these heritages were burnt clay bricks, stones, mud mortars, and lime mortars. This study examines the technical aspects such as material properties (compressive strength, bending strength, mechanical properties), and composition of mortars according to their use in different locations and types of structures, even within the same building. The study acknowledges the Department of Archaeology’s preservation and monument act, highlighting the potential for material reuse in heritage restoration. The primary aim of this study is to comprehensively understand and analyze the strength of antiquated materials and traditional mortars used in historical construction and restoration. It provides practical recommendations for future preservation efforts.

Identification of the Role of Kitchen and the Use of Traditional Cooking Tools in the Eating Culture of the Baduy Tribe Community

Baduy is one of the tribes in Indonesia that applies a living system in line with the principle of preserving nature. This principle is involved in agriculture and daily life, one of which is in cooking utensils. This study was conducted to determine the culture of cooking in the Baduy community by identifying the role of the traditional kitchen and the use of conventional cooking utensils. The research was conducted in Baduy Luar Village (Kadugketug Village, Balimbing Village) and Baduy Dalam (Cibeo Village) Kanekes Village, Leuwidimar District, Lebak Regency, Banten Province. Data was collected using field observation and interviews with community leaders and the Baduy community. The results showed that the traditional Baduy kitchen functions as a place to cook, store kitchen utensils, store foodstuffs (rice, firewood, and vegetables), a place to eat, and a place to carry out traditional ceremonies. The Baduy community has a kitchen and food culture that still maintains the values of local wisdom. It can be seen in kitchen utensils and traditional tableware made from natural materials such as clay (Hawu, barrels, traditional mortar, and braziers), wood (trays, kelaci, centong, cutting boards, matches, sulu, kalo), bamboo (haseupan, boboko, hihid, nyiru, and lodong), and coconut shells. some other equipment made from the chopper (seeng), stainless steel (kekenceng and pariuk).

Evaluation of Thermochemical Treatments for Rice Husk Ash Valorisation as a Source of Silica in Preparing Geopolymers.

The use of geopolymers has revolutionized research in the field of construction. Although their carbon footprint is often lower than that of traditional mortars with Portland cement, activators such as sodium silicate have a high environmental impact in the manufacturing of materials. Employing alternative alkali sources to produce geopolymers is necessary to obtain materials with a lower carbon footprint. The present research explores the use of rice husk ash (RHA) as an alternative source of silica to produce alkaline activators by four methods: reflux; high pressure and temperature reaction; thermal bath at 65 °C; and shaking at room temperature. To evaluate the efficiency of these methods, two types of experiments were performed: (a) analysing silica dissolved by the filtering/gravimetric method; and (b) manufacturing mortars to compare the effectiveness of the treatment in mechanical strength terms. The percentages of dissolved silica measured by the gravimetric method gave silica dissolution values of 70-80%. The mortars with the best mechanical strength results were the mixtures prepared with the thermal bath treatment at 65 °C. Mortar cured for 1 day (at 65 °C), prepared with this activator, yielded 45 MPa versus the mortar with commercial reagents (40.1 MPa). It was generally concluded that utilising original or milled RHA in preparing activators has minimal influence on either the percentage of dissolved silica or the mechanical strength development of the mortars with this alternative activator.

Hybrid BO-XGBoost and BO-RF Models for the Strength Prediction of Self-Compacting Mortars with Parametric Analysis.

Self-compacting mortar (SCM) has superior workability and long-term durable performance compared to traditional mortar. The strength of SCM, including both its compressive and flexural strengths, is a crucial property that is determined by appropriate curing conditions and mix design parameters. In the context of materials science, predicting the strength of SCM is challenging because of multiple influencing factors. This study employed machine learning techniques to establish SCM strength prediction models. Based on ten different input parameters, the strength of SCM specimens were predicted using two different types of hybrid machine learning (HML) models, namely Extreme Gradient Boosting (XGBoost) and the Random Forest (RF) algorithm. HML models were trained and tested by experimental data from 320 test specimens. In addition, the Bayesian optimization method was utilized to fine tune the hyperparameters of the employed algorithms, and cross-validation was employed to partition the database into multiple folds for a more thorough exploration of the hyperparameter space while providing a more accurate assessment of the model's predictive power. The results show that both HML models can successfully predict the SCM strength values with high accuracy, and the Bo-XGB model demonstrated higher accuracy (R2 = 0.96 for training and R2 = 0.91 for testing phases) for predicting flexural strength with low error. In terms of compressive strength prediction, the employed BO-RF model performed very well, with R2 = 0.96 for train and R2 = 0.88 testing stages with minor errors. Moreover, the SHAP algorithm, permutation importance and leave-one-out importance score were used for sensitivity analysis to explain the prediction process and interpret the governing input variable parameters of the proposed HML models. Finally, the outcomes of this study might be applied to guide the future mix design of SCM specimens.

Sustainable Approach of Using Arundo donax Leaves Reinforced Cement Mortar/Fly Bottom Ash Composites.

Earlier research suggested using ash to substitute cement, whereas other studies looked at the possibility of using plant-derived agricultural wastes as fiber reinforcement in cement applications. This study offered an environmentally friendly option to change traditional mortars by replacing cement with fly bottom ash (FBA) waste at 10, 20, 30, and 40 wt %. Likewise, Arundo donax leaves (ADL) were employed to reinforce the modified cement mortars at 0.4, 2, 5, and 7 wt %. X-ray diffraction analysis of used materials was performed. The morphology of composites made with FBA and ADL was investigated using scanning electron microscopy. Moreover, the density, water uptake, thermal conductivity, energy gain, and carbon dioxide (CO2) emissions of the prepared composites were discussed. Their flexural strength, compressive strength, and displacement were also compared. Results revealed that the addition of FBA in the mortar matrix has a positive effect on decreasing the thermal conductivity and lightness of the mortar. In addition, 20 wt % of cement replacement by FBA guarantees simultaneously moderate mechanical properties, nearly 51% of energy gain, and 20% of total CO2 emission reduction. In the same, adding ADL to the 20wt %FBA mortar reduced the thermal conductivity and the lightness of the mortar. The 0.4 wt % ADL reinforcement ensured 59% energy gain and 6% of total CO2 emission reduction. A major amelioration was observed in the compressive strength (an increase of 14%) and in the plasticity (an increase of 27%) of the considered composite materials. In conclusion, using FBA as a cement replacement with low ADL content inclusion results in a thermal-resistant composite with reasonable durability and strength.

In-plane shear strengthening of traditional unreinforced masonry walls with near surface mounted GFRP bars

In this study, the effectiveness of Near Surface Mounted (NSM) method, for in-plane shear strengthening of traditional and historical Unreinforced Masonry (URM) walls, is investigated through a comprehensive experimental study. For this purpose, square solid clay brick masonry wallettes (42 samples) with three different types of traditional mortars including gypsum mortar, lime-cement-sand mortar and lime-sand mortar are prepared and retrofitted with NSM Glass Fiber Reinforced Polymer (GFRP) bars. Then, diagonal shear tests are conducted to evaluate the in-plane shear behavior of the masonry wallettes. The effects of some key variables such as wall thickness, the retrofitted face of the wall, reinforcement ratio, and the type of paste for mounting the reinforcing bars, on the effectiveness of the retrofitting method are investigated. The results of the tests are presented in terms of the failure modes and the lateral shear stress-drift curves of the test specimens. Accordingly, the retrofitting method can enhance the in-plane shear strength, and the ultimate lateral drift capacity of the URM wallettes. According to the test results, the type of filler paste and reinforcement ratio influence the strength enhancement of the test specimens. Furthermore, in specimens retrofitted with the one-side retrofitting scheme, due to the asymmetry of walls under in-plane loads, an unexpected out-of-plane deformation is induced in the walls under in-plane load which adversely affects its global behavior.

Uticaj industrijskih nusproizvoda na svojstva geopolimernih kompozita na bazi elektrofilterskog pepela

Geopolymers are materials made of chain molecules incurred by polymerization of geopolymer binders. geopolymers are defined as a solid and stabile aluminosilicate materials, made of industrial byproducts and liquid solutions. The experimental part of the dissertation, contains the results of physical-mechanical, microscopic and durability properties of geopolymer mortars and concrete based on fly ash. For the purpose of determining the effect of different byproducts on characteristics of geopolymer mixtures, 24 batches of mortar and 8 batches of concrete were made and tested. (converter slag, wood biomass ash, red mud, and waste glass) in the amount of 5% - 100% with different steps of replacement in relation to to the binder mass. The samples of geopolymer mortar and concrete were cured at an ambient temperature According to the test results some recommendations for the possible application of fly ash and other industrial byproducts for making geopolymer mortars and concretes are made. Tested materials might be used as construction building materials and according to their physical-mechanical characteristics and durability properties, they can be alternative solution for the traditional mortar and concrete mixtures.

Estudios geológicos, biológicos y físico-químicos para la conservación y restauración de la fuente de la plaza Weyler (Santa Cruz de Tenerife, España)

This work presents the set of preliminary studies for the conservation and restoration of the fountain in plaza Weyler (Santa Cruz de Tenerife). The working methodology is interdisciplinary and aims to identify and characterize the construction materials, along with the products generated in the alteration processes, to determine the mechanisms and causes of deterioration. Two marbles of different origins belonging to two construction phases of the aforementioned square, a traditional mortar of limestone and sand as mortar, calcareous concretions resulting from filtrations and biological colonization by microalgae have been identified. A method of non-invasive analysis has been used to determine the extent of certain pathologies. In this way, it will be possible to define a specific proposal of action to deal with the pathologies affecting this cultural asset.

Solid waste-based dry-mix mortar using fly ash, carbide slag, and flue gas desulfurization gypsum

The hydration characteristics, performance, and economic feasibility of inorganic cementitious materials prepared using circulating fluidized bed fly ash (FA), carbide slag (CS), and flue-gas-desulfurization gypsum (FGDG) are investigated, focusing particularly on FA-CS binary and FA-CS-FGDG ternary cementitious systems. Experimental results show that the compressive strength of the binary system is less than that of the ternary one. The ternary cementitious material exhibits strong synergistic effects, as the 28 days compressive strength of the ternary system can reach 6.35 MPa, suggesting that it has good prospects for practical application. A dry-mixed mortar using the material has been manufactured and tested in a pilot project; it meets Chinese government quality standards and reduces cost and carbon emissions relative to traditional mortar. The 28 days compressive strength of dry mix mortar can reach 13.1 MPa, the production cost of solid waste-based dry-mixed mortar was reduced by approximately 48.8%, and the carbon dioxide emission reduction ratio was 82.9%.

Production of the Traditional Organic Mortars of Padmanabhapuram Palace—A Characterization Study on the Simulated Mortars for Their Compatibility

The scientific investigation performed on the different mortar typologies of the Padmanabhapuram Palace mortars in a previous study led to the formulation of a similar traditional mortar. The outcome of the study was an increase in the carbonation action and mechanical strength of the mortar compared to conventional lime mortar, primarily due to the fermented organics such as aloe vera, cactus, kadukkai, hibiscus, jaggery, and neelamari. The transformation of portlandite crystals to calcite, along with the early developed C-S-H and C-A-S-H hydrated products reported by the XRD analysis. The bio-organic spectral peaks for compounds such as carbohydrates, polysaccharides, and fatty acids were observed in the FT-IR investigation, which corroborates the XRD mineralogical results. The calcite decomposition is detected in the TGA analysis in the temperature range of 700–750 °C, with a maximum weight loss of approximately 35–37% for the aloe vera lime mortar. The addition of fermented organic extracts to the extent of 5% was found to increase the internal and external carbon absorption of the aloe vera and cactus mortars compared to conventional lime mortars. The mechanical strength of the organic lime mortar reported as 2.5 MPa, and 1.5 MPa for the reference mortar. The carbonation and hydraulic reactions due to the presence of polysaccharides, fatty acids, carbohydrates, and proteins in the formulation enhanced the compressive strength of the compatible mortar. The prepared compatible mortar will support the revival of the 400-year-old practice of the application of Palace mortars.

SPSS ve ANFİS ile Farklı Hafif Agregaların Kompozit Harç Üretiminde Teknik Değerlendirilmesi

In today's construction industry, the production and use of the next generationof materials is becoming increasingly common. These materials; It isused in the formofpaper block handmen,plate products and composite mortars. Especially in recent years, the development of lightweight, flexible, outdoor resistant lightweight aggregate mortar products within the scope of energy efficient products in buildings has also become a necessity. Therefore, in this article, a series of plaster pilgrim samples are prepared in composite form with polymer component by classifying light aggregates of different origin in the size range of 0.5-1 mm and 1-2 mm and using them as the main raw material. In addition, in order to make technical comparison in experimental studies, control mortar samples, which are called traditional mortar used in exterior applications of existing buildings in the construction sector, are also designed. Within the scope of the study, all mortar samples were analyzed within the scope of TS EN 998-1 standard and other related standards in force today and technical findings were examined in detail in the article. In addition, the parameters affecting the result were determined with SPSS (V26) to determine the effectiveness of the experiment input values. Data were trained with ANFIS using parameters affecting the result and results were checked with test data.

An experimental study on the mechanical properties of solid clay brick masonry with traditional mortars

An experimental study is carried out to investigate the mechanical properties of clay brick masonry fabricated using traditional mortars. In this regard, four types of mortar whose frequent uses in Iranian traditional and historical monuments have been reported in the literature are selected. These mortars are gypsum mortar and three types of lime-based mortars including, Sarooj, lime-sand mortar, and lime-cement-sand mortar. In this study, tests on brick units, mortar specimens, masonry prisms and wallettes are conducted. The compressive stress-strain behavior, compressive strength, elastic modulus, and rupture modulus of mortars are determined from the standard tests. Moreover, the compression test of masonry prisms, direct shear test of brick-mortar bond, and diagonal shear test of masonry wallettes are carried out. The compressive stress-strain behavior of masonry and the shear bond strength of brick-mortar interface are determined from the tests on masonry prisms. Furthermore, shear stress-strain behavior of masonry wallettes is evaluated through diagonal shear tests. Some key mechanical properties of masonry wallettes such as modulus of rigidity and Poisson's ratio are also found from the test results. Accordingly, the brick-mortar bond governed the in-plane shear behavior of the masonry wallettes in diagonal shear tests. Furthermore, the highest compressive strength, elastic modulus, and diagonal shear strength belong to the masonry fabricated with gypsum mortar. By using the results of the experimental program, the applicability of some well-known empirical formulations for estimating the compressive strength of masonry prisms as well as the accuracy of idealized stress-strain models proposed for masonry material, are assessed.

Influence of Anti-cracking Fiber on Properties of Traditional Sticky Rice-lime Mortar

ABSTRACT Traditional sticky rice-lime mortar plays an important role in the restoration of Chinese historical buildings. However, its application in ancient building restoration is restricted due to some shortcomings of lime-based materials such as high shrinkage, low hardness in the early phase, cracking during carbonation, etc. In order to make better use of sticky rice-lime mortar, the research presented in this article evaluates the influence of admixtures (flax fiber, polypropylene fiber, and paper fiber) on the properties of traditional sticky rice-lime mortar by testing compressive and flexural strengths, surface hardness, drying shrinkage, water absorption, freezing-thawing cycles, carbonation degree, and through performing X-ray diffraction analysis (XRD) and scanning electron microscopy (SEM). Results revealed that three types of fibers ameliorated the mechanical strength, anti-shrinkage performance, durability, and microstructure of traditional sticky rice-lime mortar. 1.5% paper fiber was the most effective admixture to increase the mechanical properties and reduce the water absorption rates, and it improved the freeze–thaw cycles by more than 10 times; the incorporation of polypropylene fiber significantly reduced the drying shrinkage rates. In the practice of brick-stone cultural heritage conservation, it is recommended to consider adding paper fibers to improve the comprehensive performance of traditional sticky rice-lime mortar and adding polypropylene fibers to improve shrinkage resistance.