scholarly journals Recycled PET Sand for Cementitious Mortar

Materials ◽  
2021 ◽  
Vol 15 (1) ◽  
pp. 273
Author(s):  
Angélica Faria Campanhão ◽  
Markssuel Teixeira Marvila ◽  
Afonso R. G. de Azevedo ◽  
Tulane Rodrigues da Silva ◽  
Roman Fediuk ◽  
...  

Cementitious materials cause a great impact on the environment due to the calcination of clinker and the extraction of non-renewable mineral resources. In this work, the replacement of quartz sand from the river by PET sand was evaluated at levels of 10%, 20%, and 30%. Tests were performed in the fresh state through consistency, air retention, density, and incorporated air and in the hardened state for compressive strength, flexural strength, density, capillarity, and water absorption. The results show that PET sand is viable in contents of up to 10%, improving the mechanical properties of the mortar and without compromising its workability and incorporated air properties. Above that level, the loss of properties is very excessive, mainly of workability and incorporated air. The incorporated air of the 30% composition, for example, reaches 24%, an excessive value that impacts the properties of the hardened state, making it impossible to use the material at levels greater than 20%. It is concluded that the use of recycled PET sand is a possibility that contributes to sustainable development, as it reduces the extraction of quartz sand from the river, a non-renewable mineral resource.

2016 ◽  
Vol 138 (3) ◽  
Author(s):  
João Victor Staub de Melo ◽  
Glicério Trichês

This paper reports the results obtained in a study on the effect of the addition of TiO2 nanoparticles on the mechanical properties and microstructural characteristics of photocatalytic concretes. In the hardened state, tests to determine the compressive strength and modulus of elasticity were carried out. Also, microstructural aspects of the samples were investigated. In the fresh state, the influence of the addition of TiO2 on the concrete compaction and conduction calorimetry curves was evaluated. The results obtained indicated a better mechanical and microstructural behavior of concrete with addition of TiO2.


2020 ◽  
Vol 25 (1) ◽  
Author(s):  
Hinoel Zamis Ehrenbring ◽  
Maira Janaina Ott ◽  
Bianca Carlin Cadore ◽  
Diego Logue do Espirito Santo ◽  
Bernardo Fonseca Tutikian

ABSTRACT The lack of control regarding waste generation is a problem still faced by the construction industry, whereas its inputs could be used in the production of new cementitious composites, maintaining the quality, performance and sustainability of structures. This study developed grouts through the substitution of natural aggregate for residues of crushed ceramic bricks, evaluating its fresh state and mechanical properties. The samples displayed loss of workability and initial slump in fresh state, besides loss of compressive strength, elastic modulus, total water absorption and capillary water absorption in hardened state. In addition, composites with grog presented less consistency in fresh state when compared to the reference sample. The differences were even greater over time. As for the hardened state, the compressive strength of the samples was similaramong them at both ages, and all results remained above 14 MPa at 28 days, as required by ASTM C476, hence being characterized as structural grouts for masonry. For the elastic modulus test, the results were higher for samples with lower amounts of waste due to less internal voids and higher volume of natural aggregates. The substitution of natural aggregate for civil construction waste (CCW) in the mixtures increased void ratio and water absorption, while causing the lowest specific gravities of the research. Overall, the sample that presented the most satisfactory values was CCW 25%, showing that it is possible to obtain benefits from waste produced in factories and buildings, even for higher replacement levels, occasionally


Today’s world is always leads to development in technology as well as the economic growth though sometime these will affect the environment badly. That’s why world environmental commission coined the termed called sustainable development where development takes place without hampering the others’ needs. Concrete industry is rapidly growing industry in India which consumes lots of natural resources during the production of concrete. Here Stone dust is used as a sustainable material in place of sand partially. M25 grade of concrete has been chosen for the experiments. Different mechanical properties of concrete like compressive strength, Split tensile, flexural strength etc. and Microstructural features like SEM, EDX have been included in this study. Compressive Strength and flexural strength test results shown the increase in the strength. Sulphate Resistance Properties have been tested by curing the cubes in the MgSO4 solution and increase in weight has been observed. Similarities are found in the SEM pictures


This chapter discusses the effects of metakaolin (MK) on geopolymer mortar and concrete industries. The research topics of MK-based geopolymer cover reaction mechanisms and kinetics. This chapter aims at augmenting knowledge about enhancing mechanical properties of geopolymer mortars/concrete using MK. Specifically, this chapter presents literature studies as well as current experimental studies which delineate the effect of MK on fresh and hardened-state properties of geopolymer mortars (GPMs). Properties and characteristics of metakaolin are explained followed by properties of fresh MK mortars. Properties of hardened MK concrete and durability aspects of MK mortars are explained. Applications of MK-based geopolymers and metakaolin-based geopolymers as repair materials are also included in this chapter. The results of using MK-based GPMs revealed improved workability, enhanced setting time, increased density, higher compressive strength, flexural strength, and resistance against acid attack than conventional ordinary portland cement mortar/concrete.


2019 ◽  
Vol 12 (1) ◽  
pp. 31-38 ◽  
Author(s):  
N. SCHWANTES-CEZARIO ◽  
M. F. PORTO ◽  
G. F. B. SANDOVAL ◽  
G. F. N. NOGUEIRA ◽  
A. F. COUTO ◽  
...  

Abstract This study aims to evaluate the influence of B. subtilis AP91 spores addition on the mechanical properties of mortars. B. subtilis strain AP91, isolated from rice leaves of the needle variety, which has an early cycle of production, was used at the concentration of 105 spores/mL in mortars with cement-to-sand ratio of 1:3 (by weight) and water-to-cement ratio (w/c) of 0.63. These spores were added in two different ways: in the mixing water and by immersion in a solution containing bacterial spores. Scanning Electron Microscope (SEM) analysis showed crystals with calcium peaks on the EDS, which possibly indicates the presence of bioprecipitated calcium carbonate. The results obtained in the mechanical analysis showed that the bioprecipitation of CaCO3 by B. subtilis strain AP91 was satisfactory, particularly when the spores were added in the mixing water, increasing the compressive strength up to 31%. Thus, it was concluded that the addition of B. subtilis AP91 spores in the mixing water of cement mortars induced biocementation, which increased the compressive strength. This bioprecipitation of calcium carbonate may very well have other advantageous consequences, such as the closure of pores and cracks in cementitious materials that could improve durability properties, although more research is still needed on this matter.


2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Liliana Ávila Córdoba ◽  
Gonzalo Martínez-Barrera ◽  
Carlos Barrera Díaz ◽  
Fernando Ureña Nuñez ◽  
Alejandro Loza Yañez

Concretes consisting of portland cement (OPC), silica sand, gravel, water, and recycled PET particles were developed. Specimens without PET particles were prepared for comparison. Curing times, PET particle sizes, and aggregate concentrations were varied. The compressive strength, compressive strain at yield point, and Young modulus were determined. Morphological and chemical compositions of recycled PET particles were seen in a scanning electron microscopy. Results show that smaller PET particle sizes in lower concentrations generate improvements on compressive strength and strain, and Young’s modulus decreases when the size of PET particles used was increased.


2011 ◽  
Vol 311-313 ◽  
pp. 1949-1952 ◽  
Author(s):  
Ying Li Gao ◽  
Ling Cheng

Cement based composite cementitious material containing steel slag used in road has been prepared to deal with the current situation that the transportation carbon emission increased year by year. In this material, 40% cement has been replaced by equivalent steel slag, which has the ability of CO2sequestration. This paper studied the CO2sequestration effect and the mechanical properties of the pure cement, the pure steel slag, and the cement based composite cementitious materials containing steel slag. It has been shown that the cement based composite cementitious materials containing steel slag have excellent CO2sequestration property. The mass fraction growth rate of carbon reached 10.86% after 1 hour carbonation experiment, the value between which of pure cement and pure steel slag, and the compressive strength of the composite cementitious materials at 28-day age can reach 45.3MPa, meeting the requirements of road.


2020 ◽  
Vol 323 ◽  
pp. 01017
Author(s):  
Devid Falliano ◽  
Dario De Domenico ◽  
Salvatore Quattrocchi ◽  
Paolo Cosenza ◽  
Giuseppe Ricciardi ◽  
...  

This contribution focuses on the design and the characterization of innovative mix designs of high consistency mortars with biochar additions in different percentage with respect to the cement weight. Biochar is a by-product material that gives the cementitious mix a sustainable connotation from an environmental point of view. The mix designs presented here are characterized by a good dimensional stability in the fresh state, peculiarity that gives them the possibility to be extruded and so, to be used in automated construction processes. In addition to the mechanical properties (flexural and compressive strength), the assessment of the CO2 emission of representative mixes is presented. Different biochar content and maximum diameter of the aggregate are studied, obtaining interesting indications on these parameters to optimize mechanical properties. Finally, on the basis of the CO2 emission assessment, certain venues for future research work to minimize CO2 emissions are reported.


2019 ◽  
Vol 7 (8) ◽  
pp. 252 ◽  
Author(s):  
Yu Dai ◽  
Feiyue Ma ◽  
Xiang Zhu ◽  
He Liu ◽  
Zhonghua Huang ◽  
...  

With the decrease of primary resources in recent years, deep seabed mineral resources, especially the massive sulfides, are of extensive research significance. In this paper, firstly, the uniaxial compressive strength (UCS) test and triaxial compressive strength (TCS) test on the seafloor massive sulfides (SMS) samples from three different segments are conducted to obtain the key mechanical properties, including the cohesive force, internal friction angle, compressive strength, elastic modulus and Poisson’s ratio. Then, by leveraging the PFC3D code, the uniaxial and triaxial numerical simulations of SMS are performed. During this process, the micro properties in the simulation are altered through a calibration process until they match the macro properties of the SMS samples measured in the laboratory tests. Finally, the micro properties are applied to simulate the cutting process of single cutting pick and two adjacent cutting picks; meanwhile, the cutting force in the fragmentation process of SMS is monitored and collected. This research can provide some guidance for the mining simulation of SMS and effectively predicting the maximum force on the cutting pick.


2018 ◽  
Vol 199 ◽  
pp. 07006
Author(s):  
Md Shamsuddoha ◽  
Götz Hüsken ◽  
Wolfram Schmidt ◽  
Hans-Carsten Kühne ◽  
Matthias Baeßler

Grouting is a universal repair and strengthening technique, which is constantly used for structural remediation of concrete components, trenches, mine subsidence, dam joints, restoration of masonry structures, and geological stabilizations. Having an extremely small particle size of only few microns, ultrafine cements are ideal for grouting applications due to their superior permeability and compressive strength properties of the hardened cement paste compared to that of the less-expensive, but coarser ordinary Portland cements. Supplementary cementitious materials (SCMs) are often used to replace ultrafine cement in order to modify certain properties and to reduce costs. The aim of this experimental study is to investigate the effect of three supplementary materials: microsilica (MS), fly ash (FA), and metakaolin (MK) on the workability, and mechanical properties of an ultrafine cement based grout with a constant water-binder ratio and constant superplasticizer content. Maximum percentages of replacement with ultrafine cement were 6% by volume of cement for MS and 16% for FA, and MK. In general, results suggest that the workability is improved by addition of FA, whereas is reduced, when modified with MS and MK. The compressive strength of grout after cement replacement remains comparable to that of pure cement grout. However, there is a tendency of the MS to positively affect the compressive strength opposite to FA, whereas flexural strength is positively affected by FA. Based on the results, it is evident that grouts with Hägerman cone flow more than 500 mm and compressive strength of more than 90 MPa after 28 days can be produced.


Sign in / Sign up

Export Citation Format

Share Document