Utilization of textile fibres from worn automobile tires in cement based mortars

This research paper focuses on the properties of laboratory made cement mortars modified with textile from worn automobile tires. Textile, in the form of fibres, has been added to cement mortars at various percentages of total cement mortar volume, which ranged from 0-2.0%. Properties of mortartextile- aggregates mixtures such as consistency-workability-, bulk density as well as mechanical ones such as dynamic modulus of elasticity, compressive and flexural strengths have been studied. Moreover, water absorption under vacuum and capillarity by suction of such mixtures have been measured, as a preliminary examination of cement mortars’ durability. The study of the mixtures has been completed by the observation of their microstructure. All properties have been tested according to European Specifications. Laboratory results showed that properties of cement mortars, modified with textile from worn automobile tires, were found to be familiar to the ones of the control mixture (with no additive). Incidentally, a solid waste material such as textile fibers from worn automobile tires can be utilized properly in cement products providing an opportunity to recycle non-reusable end of life tires and as a result contributing to the protection of the environment.

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Recycled Cellulose Fiber Reinforced Plaster

Materials ◽

10.3390/ma14112986 ◽

2021 ◽

Vol 14 (11) ◽

pp. 2986

Author(s):

Nadezda Stevulova ◽

Vojtech Vaclavik ◽

Viola Hospodarova ◽

Tomáš Dvorský

Keyword(s):

Thermal Conductivity ◽

Water Absorption ◽

Bulk Density ◽

Mechanical Performance ◽

Cement Mortar ◽

Waste Paper ◽

Cellulose Content ◽

Fiber Reinforced ◽

Adhesive Properties ◽

Cement Mortars

This paper aims to develop recycled fiber reinforced cement plaster mortar with a good workability of fresh mixture, and insulation, mechanical and adhesive properties of the final hardened product for indoor application. The effect of the incorporation of different portions of three types of cellulose fibers from waste paper recycling into cement mortar (cement/sand ratio of 1:3) on its properties of workability, as well as other physical and mechanical parameters, was studied. The waste paper fiber (WPF) samples were characterized by their different cellulose contents, degree of polymerization, and residues from paper-making. The cement to waste paper fiber mass ratios (C/WPF) ranged from 500:1 to 3:1, and significantly influenced the consistency, bulk density, thermal conductivity, water absorption behavior, and compressive and flexural strength of the fiber-cement mortars. The workability tests of the fiber-cement mortars containing less than 2% WPF achieved optimal properties corresponding to plastic mortars (140–200 mm). The development of dry bulk density and thermal conductivity values of 28-day hardened fiber-cement mortars was favorable with a declining C/WPF ratio, while increasing the fiber content in cement mortars led to a worsening of the water absorption behavior and a lower mechanical performance of the mortars. These key findings were related to a higher porosity and weaker adhesion of fibers and cement particles at the matrix-fiber interface. The adhesion ability of fiber-cement plastering mortar based on WPF samples with the highest cellulose content as a fine filler and two types of mixed hydraulic binder (cement with finely ground granulated blast furnace slag and natural limestone) on commonly used substrates, such as brick and aerated concrete blocks, was also investigated. The adhesive strength testing of these hardened fiber-cement plaster mortars on both substrates revealed lime-cement mortar to be more suitable for fine plaster. The different behavior of fiber-cement containing finely ground slag manifested in a greater depth of the plaster layer failure, crack formation, and in greater damage to the cohesion between the substrate and mortar for the observed time.

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ASSESSMENT OF MIX PROPORTIONS FOR DEVELOPING LIGHTWEIGHT CEMENTITIOUS COMPOSITES WITH WOOD WASTES

Revista Árvore ◽

10.1590/1806-90882017000100003 ◽

2017 ◽

Vol 41 (1) ◽

Author(s):

Monica Garcez ◽

Estela Garcez ◽

Aline Machado ◽

Darci Gatto

Keyword(s):

Mechanical Properties ◽

Compressive Strength ◽

Water Absorption ◽

Bulk Density ◽

Modulus Of Elasticity ◽

Dynamic Modulus ◽

Void Ratio ◽

Eucalyptus Grandis ◽

Cementitious Composites ◽

Wood Composites

ABSTRACT The main objective of this work was to assess mix proportions for developing lightweight cementitious composites, manufactured with Eucalyptus grandis sawdust. Different wood:cement, water:cement and admixture:cement ratios were used to evaluate physical (water absorption, void ratio and density) and mechanical (compressive strength, static and dynamic modulus of elasticity) properties of the cement-wood composites. Results shows that, bulk density is directly proportional to the compressive strength and elastic modulus, and inversely proportional to the percentage of timber, considering composites with same water:cement ratio, without superplasticizer. The performance of the cement-wood composites, regarding mechanical properties, can be improved if superplasticizer is used to increase paste fluidity. Higher values of bulk density are related to lower void ratio and water absorption and higher compressive strength and modulus of elasticity.

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Incorporation of Iraqi Rocks in the Production of Eco-Friendly Cement Mortar

Engineering and Technology Journal ◽

10.30684/etj.v38i10a.1479 ◽

2020 ◽

Vol 38 (10A) ◽

pp. 1522-1530

Author(s):

Rawnaq S. Mahdi ◽

Aseel B. AL-Zubidi ◽

Hassan N. Hashim

Keyword(s):

Mechanical Properties ◽

Thermal Conductivity ◽

Compressive Strength ◽

Water Absorption ◽

Structural Properties ◽

Mechanical Milling ◽

Cement Mortar ◽

Cement Mortars

This work reports on the incorporation of Flint and Kaolin rocks powders in the cement mortar in an attempt to improve its mechanical properties and produce an eco-friendly mortar. Flint and Kaolin powders are prepared by dry mechanical milling. The two powders are added separately to the mortars substituting cement partially. The two powders are found to improve the mechanical properties of the mortars. Hardness and compressive strength are found to increase with the increase of powders constituents in the cement mortars. In addition, the two powders affect water absorption and thermal conductivity of the mortar specimens which are desirable for construction applications. Kaolin is found to have a greater effect on the mechanical properties, water absorption, and thermal conductivity of the mortars than Flint. This behavior is discussed and analyzed based on the compositional and structural properties of the rocks powders.

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A Method for Estimating the Dynamic Moduli of Cement Paste-Aggregate Interfacial Zones in Mortar

MRS Proceedings ◽

10.1557/proc-370-407 ◽

1994 ◽

Vol 370 ◽

Cited By ~ 2

Author(s):

Menashi D. Cohen ◽

Turng-Fang F. Lee ◽

Ariel Goldman

Keyword(s):

Portland Cement ◽

Silica Fume ◽

Cement Paste ◽

Modulus Of Elasticity ◽

Dynamic Modulus ◽

Dynamic Shear Modulus ◽

Interfacial Zone ◽

Dynamic Moduli ◽

Dynamic Modulus Of Elasticity ◽

Cement Mortars

AbstractThe objective of this paper is to propose a method to estimate the average values of the dynamic modulus of elasticity and the dynamic shear modulus of cement paste-aggregate interfacial zones in mortar by applying the Logarithmic Mixture Rule (LMR). Both portland cement mortars (PC mortars) and portland cement mortars with silica fume (SF mortars) are investigated and compared, The influence of silica fume on the dynamic moduli of interfacial zone is also examined. Results indicate that for the specific ingredients and mix design used, the dynamic modulus of elasticity of interfacial zone falls between 0.4 and 2.0 (×10 6 psi) for PC mortar and 1.2 to 2.2 (× 106 psi) for SF mortar. These values are lower than the values obtained for PC mortar (4.2 ×106 psi), PC paste (2.7 ×106 psi), SF mortar (4.4 ×106 psi), and SF paste (2.5 × 106 psi).

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The influence of type of cement on the degradation of microstructure and transport properties of cement mortars exposed to frost induced damage

MATEC Web of Conferences ◽

10.1051/matecconf/201817401014 ◽

2018 ◽

Vol 174 ◽

pp. 01014

Author(s):

Alicja Wieczorek ◽

Marcin Koniorczyk

Keyword(s):

Absorption Coefficient ◽

Pore Structure ◽

Water Absorption ◽

Transport Properties ◽

Cement Mortar ◽

Gas Permeability ◽

Water Absorption Coefficient ◽

Freeze Thaw ◽

Cement Mortars ◽

Small Pore

The purpose of the study is to understand how the cyclic water freezing (0, 25, 50, 75, 100 and 150 freeze-thaw cycles) impacts microstructure and transport properties of cement-based materials. Tests were conducted on cement mortars with different water/cement ratios (w/c=0.45 and 0.40) and on two types of cement (CEM I and CEM III) without air-entraining admixtures. The changes of pore size distribution and open porosity were investigated by means of mercury intrusion porosimetry. Additionally, the relationship between intrinsic permeability and the water absorption coefficient of cement mortar samples was analysed. The water absorption coefficient and gas permeability were determined using capillary absorption test and the modified RILEMCembureau method. The evolution of transport coefficients with growing number of freeze-thaw cycles were determined on the same sample. It was also established that change of pore structure (a decrease of small pore volume <100nm and increase of larger pores >100nm) induces an increase of water transport parameters such as permeability and water absorption coefficient. The higher gas permeability corresponds to the higher internal damage. In particular, it is associated with the change of cement mortar microstructure, which indicates damage of narrow channels in the pore structure of cement mortars.

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Fiber-Reinforced Mortar Incorporating Pig Hair

Advanced Engineering Forum ◽

10.4028/www.scientific.net/aef.21.219 ◽

2017 ◽

Vol 21 ◽

pp. 219-225 ◽

Cited By ~ 10

Author(s):

Gerardo Araya-Letelier ◽

Federico C. Antico ◽

Pablo Fernado Parra ◽

Miguel Carrasco

Keyword(s):

Impact Strength ◽

Bulk Density ◽

Environmental Impacts ◽

Modulus Of Elasticity ◽

Dynamic Modulus ◽

Food Industry ◽

Fiber Reinforced ◽

Dynamic Modulus Of Elasticity ◽

Cement Based Materials ◽

The Impact

Recycled fibers from food-industry could be added as reinforcement to cement-based materials. Cement-based materials perform well under compression, but tensile strength and post-cracking ductility in tension are poor. Fibers produced from steel, glass and synthetic materials, have been successfully used to overcome some of these shortcomings. Fiber-reinforced mortar has shown an increased post-cracking ductility and improved long-term serviceability due to the crack control provided by fibers. Food-industry waste disposal is globally a major concern because of its environmental impacts. For these reasons, the use of recycled materials in construction applications has been investigated over the last decades. This investigation deals with the incorporation of pig hair, which is a waste produced by the food-industry worldwide, in fiber-reinforced mortars. This composite material is intended to reduce the environmental impacts by valuing waste materials in construction applications while improving mechanical properties. To determine compressive, flexural and impact strength, bulk density, porosity and dynamic modulus of elasticity laboratory tests were conducted in mortar specimens with 0%, and 2% of pig-hair content in weight of cement. The results of this research show that the impact strength can increase up to five times when compared to plain mortar. Moreover, the compressive and flexural strengths, bulk density, porosity and the dynamic modulus of elasticity of fiber-reinforced mortar, with the aforementioned pig-hair content, are not significantly affected.

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Use of Spongilites as Pozzolanic Additives in Cement Mortars

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.325.65 ◽

2021 ◽

Vol 325 ◽

pp. 65-70

Author(s):

Martin Vyšvařil ◽

Patrik Bayer ◽

Tomáš Žižlavský

Keyword(s):

Mechanical Properties ◽

Bulk Density ◽

Frost Resistance ◽

Water Retention ◽

Cement Mortar ◽

Partial Replacement ◽

Fine Grained ◽

Natural Pozzolans ◽

Cement Mortars ◽

Pozzolanic Additives

In this study, the utilization of two types of spongilites in various addition in cement mortars has been investigated with the purpose of exploring a new application of this natural pozzolans as cement mortar additives. The influence of the addition of spongilites on the physico-mechanical properties, frost-resistance, and microstructure of cement mortars as a function of time was studied. The results revealed that the rising proportion of spongilites in cement mortars causes increase in water retention of mortars, reduction of their bulk density, increase in porosity of mortars due to the growing predominance of capillary pores maintaining sufficient mortars strengths, and slightly increase in the frost-resistance of mortars. After initial tests, partial replacement of cement in fine-grained cement mortars with hitherto unexploited spongilites seems to be very promising. Based on the achieved results, a 20% cement replacement can be recommended as optimal.

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Production of upgraded recycled aggregates from construction and demolition waste for replacement of primary sand in cement mortars

10.5194/egusphere-egu2020-5137 ◽

2020 ◽

Author(s):

Michael Galetakis ◽

Athanasia Soultana ◽

Theodoros Daskalakis

Keyword(s):

Water Absorption ◽

Cement Paste ◽

Cement Mortar ◽

Recycled Concrete ◽

Construction And Demolition Waste ◽

Recycled Aggregates ◽

Demolition Waste ◽

Cement Mortars ◽

Limestone Sand ◽

Crushed Limestone

<p>Waste concrete is the most predominant constituent material among construction and demolition waste. Recycling of this material could minimize landfilled waste and mineral resources depletion. This study investigates, in laboratory scale, the production of upgraded recycled concrete aggregates, suitable for the replacement of primary (crushed limestone sand) used in cement mortars, by means of selective crushing and autogenous grinding. These particle size reduction techniques, compared to traditional crushing/grinding, have the potential to remove the brittle cement paste from the aggregates, thus significantly improving their quality. The granulometry, the density, the water absorption (EN 13755) and the flow coefficient (EN 933-6) of the produced upgraded sand was determined and compared to crushed limestone sand. Subsequently, cement mortar specimens were manufactured using upgraded aggregates for total replacement of crushed limestone sand. Specimens were tested for their compressive and flexural strength (EN 196-1), density and water absorption. Results indicated that the upgraded recycled sand produced through the selective crushing and autogenous grinding processes had improved properties compared to the one produced by conventional crushing processes (flexural and compressive strength of cement mortar specimens were increased by 29% and 7%, respectively). However, the quality of the upgraded sand is lower than that of the primary crushed limestone. To further explore the issue, it is planned to investigate in more detail the process of autogenous grinding and to investigate the use of other selective aggregate-cement paste liberation technologies.</p>

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Damage of shotcrete under freeze-thaw loading

Journal of Civil Engineering and Management ◽

10.3846/13923730.2016.1210224 ◽

2017 ◽

Vol 23 (5) ◽

pp. 583-593 ◽

Cited By ~ 4

Author(s):

Jianxun CHEN ◽

Pengyu ZHAO ◽

Yanbin LUO ◽

Xianghui DENG ◽

Qin LIU

Keyword(s):

Computed Tomography ◽

Mass Loss ◽

Pore Structure ◽

Modulus Of Elasticity ◽

Dynamic Modulus ◽

Cement Mortar ◽

Ct Scanning ◽

Freeze Thaw ◽

Internal Pore Structure ◽

Internal Pore

The freeze-thaw durability of shotcrete can be improved by adding an air-entraining agent in cold areas. The main focus of this paper is to investigate the changes in the internal pore structure of C25 ordinary shotcrete and shotcrete mixed with a RM-YQ air-entraining agent using computed tomography (CT) scanning technique during freeze-thaw cycles. The macroscopic tests were conducted, including mass loss, dynamic modulus of elasticity and ultrasonic wave velocity tests. Results were compared, and the freeze-thaw durability characteristics of shotcrete mixed with the air-entraining agent were revealed. Adding an air-entraining agent could reduce the number of pores largely that ranged mainly from 0.01 mm2 to 1.00 mm2 (excluding the pores or bubbles < 0.01 mm2 because of the precision of the CT scanning system), and could therefore improve the initial pore structure of the formed shotcrete. During first few freeze-thaw cycles, just few small pores formed. After cement mortar fragmentations appeared, the number of small pores (0.01 mm2 to 0.50 mm2) in ordinary shotcrete increased significantly. The pore structure deteriorated largely. However, this could be prevented effectively by adding an air-entraining agent. Therefore, the freeze–thaw durability of shotcrete was improved.

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Mechanical Properties and Microstructure of Polyvinyl Alcohol (PVA) Modified Cement Mortar

Applied Sciences ◽

10.3390/app9112178 ◽

2019 ◽

Vol 9 (11) ◽

pp. 2178 ◽

Cited By ~ 2

Author(s):

Jie Fan ◽

Gengying Li ◽

Sijie Deng ◽

Zhongkun Wang

Keyword(s):

Mechanical Properties ◽

Polyvinyl Alcohol ◽

Cement Mortar ◽

Cement Matrix ◽

Hydration Products ◽

Scanning Calorimetry ◽

Large Piece ◽

Cement Mortars ◽

Compressive And Flexural Strengths ◽

Scanning Electron

The mechanical properties of cement mortars with 0~2.0% (by mass) polyvinyl alcohol (PVA) were experimentally studied, and the effects of PVA incorporation on the hydration products and microstructure of the cement mortar were determined with differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The results show that the rational content of PVA formed evenly dispersed network-like thin films within the cement matrix, and these network-like films can bridge cracks in the cement matrix and improve the mechanical properties of the cement mortar. Over- incorporation of PVA may result in the formation of large piece polymer films that coat the cement particles, delay the hydration of the cement mortar and adversely affect its performance. The mechanical properties of the cement mortar show a significant increase and then decrease with a change in the PVA incorporation. When the PVA content was 0.6% and 1.0%, the mortar had the best compressive and flexural strengths, respectively. The compressive strength of the cement mortar increased by 12.15% for a PVA content of 0.6%, and the flexural strength of the cement mortar increased by 24.83% for a PVA content of 1.0%.

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