scholarly journals Implementation of Interaction Diagram of the Properties in Fresh for Mortars with Ceramic Aggregates

2016 ◽  
Vol 61 (2) ◽  
pp. 335 ◽  
Author(s):  
Francisca Guadalupe Cabrera-Covarrubias ◽  
José Manuel Gómez-Soberón ◽  
Jorge Luis Almaral-Sánchez ◽  
Ramón Corral-Higuera ◽  
María Consolación Gómez-Soberón
Keyword(s):  
Statistical Analysis ◽  
Regression Coefficients ◽  
Design Phase ◽  
Construction Sector ◽  
Demolition Waste ◽  
Interaction Diagram ◽  
Fresh State ◽  
Hardened State ◽  
Natural Aggregates ◽  
Representative Material

As the natural resources needed for the construction sector arelimited, new practices are being adopted for the managementof waste generated nowadays, including the use of constructionand demolition waste as aggregates for concrete and mortar.Considering the different typologies in construction wastes,ceramics are the second most representative material; thereforeit is important to validate their feasibility as a total orpartial replacement of natural aggregates. This work presentsa study of the properties in fresh state (consistency, density andair content) of mortars containing aggregates obtained fromrecycled ceramics, and their influence on the subsequent propertiesin the hardened state. A statistical analysis of experimentaldata was carried out by establishing regression coefficients,and then a triple-entry graph was obtained, allowing the differentproperties of mortars to be easily linked and simplifyingthe prediction of the relationships they will present since themixture design phase. 

scholarly journals Fresh-State Properties of Mortars with Recycled Glass Aggregates: Global Unification of Behavior

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
José Manuel Gómez-Soberón ◽  
Francisca Guadalupe Cabrera-Covarrubias ◽  
Jorge Luis Almaral-Sánchez ◽  
María Consolación Gómez-Soberón
Keyword(s):  
Statistical Analysis ◽  
Economic Benefits ◽  
Waste Glass ◽  
Experimental Results ◽  
Construction Sector ◽  
Triple Interaction ◽  
Recycled Glass ◽  
Air Content ◽  
Fresh State

Due to the current problems related to the generation of diverse wastes and the extraction of nonrenewable materials to be used in the construction sector, the alternative use of waste glass could be a sustainable option with environmental and economic benefits, in case of being feasible its use as a replacement of the usual aggregates to manufacture recycled mortars. In this research, one presents a study of the fresh-state properties of the mortars containing 15, 30, 60, and 100% recycled glass aggregates as a replacement for the usual aggregate, providing the experimental results of consistency, density, and air content. Using the experimental results, and by means of a numerical and statistical analysis of these, a diagram of triple interaction that allows us to unify the behavior of the studied properties is constituted; making feasible with this, the prediction of the behavior of these properties with respect to variables as their ratio water/cement, aggregate/cement, and different percentages of replacement of aggregates.

Influence of Moisture States of Recycled Coarse Aggregates on the Slump Test

2013 ◽  
Vol 742 ◽  
pp. 379-383 ◽  
Author(s):  
Julia García González ◽  
Desirée Rodríguez Robles ◽  
Andrés Juan Valdés ◽  
Julia M. Morán del Pozo ◽  
M. Ignacio Guerra Romero
Keyword(s):  
Free Water ◽  
Construction And Demolition Waste ◽  
Recycled Aggregate ◽  
Recycled Aggregates ◽  
Construction Sector ◽  
Inexpensive Method ◽  
Demolition Waste ◽  
Coarse Aggregates ◽  
Subsequent Elimination ◽  
Natural Aggregates

The use of recycled aggregate to produce new concretes has become increasingly widespread, and numerous studies have demonstrated that the final product performs similarly to traditional concrete. However, construction and demolition waste (CDW) presents certain characteristics which could limit its acceptance in the construction sector due to worse performance than natural aggregates. One example of this is water absorption, which in recycled aggregates reaches such high values that the amount of free water calculated for mixing the concrete is affected, consequently impacting on the concrete's properties, especially consistency. This paper reports the possibility of solving this problem with a simple and inexpensive method; pre-saturation of recycled aggregates prior to adding them to the mix. The results of two different pre-treatments are compared; one consisted of immersing the aggregates in water for 10 minutes and the other, in addition to the above procedure, included a brief period of air drying and subsequent elimination of surface water from the aggregate. Both pre-treatments were found to solve the problem of consistency.

scholarly journals Evaluation of mechanical properties of grouts substituting the natural coarse aggregate for ceramic civil construction waste

2020 ◽  
Vol 25 (1) ◽  
Author(s):  
Hinoel Zamis Ehrenbring ◽  
Maira Janaina Ott ◽  
Bianca Carlin Cadore ◽  
Diego Logue do Espirito Santo ◽  
Bernardo Fonseca Tutikian
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Elastic Modulus ◽  
Water Absorption ◽  
Reference Sample ◽  
Construction Waste ◽  
Natural Aggregate ◽  
Fresh State ◽  
Hardened State ◽  
Natural Aggregates

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

scholarly journals The The Effects of Recycled Tire Rubbers and Steel Fibers on the Performance of Self-compacting Alkali Activated Concrete

2021 ◽  
Author(s):  
Necip Altay Eren ◽  
Radhwan Alzeebaree ◽  
Abdulkadir Çevik ◽  
Anıl Niş ◽  
Alaa Mohammedameen ◽  
...  
Keyword(s):  
Granulated Blast Furnace Slag ◽  
Structural Applications ◽  
Fresh State ◽  
Hardened State ◽  
Strength And Deformation ◽  
Natural Aggregates ◽  
Mechanical Performances ◽  
Mechanical Strengths ◽  
Alkali Activated Concrete ◽  
Alkali Activated

In this study, the effects of recycled tire rubbers (RTR) and steel fiber (SF) on the fresh and hardened state properties of the self-compacted alkali activated concrete (SCAAC) were investigated. The ground granulated blast furnace slag, 1 % hooked-end SF, and two types of RTR were utilized. The crumb rubbers (CR) and tire rubber chips (TCR) were used as a substation to natural aggregates at substation levels of 10 % and 15 %. The fresh state performances were evaluated by T50 value, slump flow, V-funnel, and L-Box tests, while mechanical performances were assessed through compressive, flexural, and splitting tensile strength tests. Also, detailed crack and microstructural analyses were conducted. The RTR adversely affected the fresh state properties, which reduced more with SF inclusions. Among the RTR, the TR specimens exhibited lower fresh state performance than the CR specimens. Similar mechanical strengths were obtained on the TR and CR specimens under the same replacement ratios. However, TR specimens exhibited higher deformation capacities than the CR specimens, when SF was utilized. The SCAAC specimens with 1 % SF and 15 % RTR showed more and wider flexural cracks, higher mechanical strength, and deformation capacity, which can be utilized in structural applications, particularly in high seismic zones.

The Traceability of Construction and Demolition Waste in Flanders via Blockchain Technology: A Match Made in Heaven?

2021 ◽  
Vol 18 (4) ◽  
pp. 347-369
Author(s):  
Jonas Voorter ◽  
Christof Koolen
Keyword(s):  
Circular Economy ◽  
Construction And Demolition Waste ◽  
Waste Processing ◽  
Construction Sector ◽  
Sustainable Society ◽  
Demolition Waste ◽  
Blockchain Technology ◽  
Legal Case ◽  
Made In

Abstract The construction sector plays a crucial role in the transition to a circular economy and a more sustainable society. With this objective in mind, Flanders – the Dutch speaking part of Belgium – makes use of a traceability procedure for construction and demolition waste in order to guarantee that value can be derived from downstream waste processing activities. This article takes this traceability procedure as a legal case study and examines if the use of blockchain technology could lead to even stronger supply chains, better data management, and, more generally, a smoother transition to circular practices in the construction sector.

scholarly journals Effect of Polypropylene Fibre Addition on Properties of Geopolymers Made by 3D Printing for Digital Construction

Materials ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 2352 ◽  
Author(s):  
Behzad Nematollahi ◽  
Praful Vijay ◽  
Jay Sanjayan ◽  
Ali Nazari ◽  
Ming Xia ◽  
...  
Keyword(s):  
3D Printing ◽  
Bond Strength ◽  
Fibre Volume ◽  
Interface Plane ◽  
Flexural Performance ◽  
Fresh State ◽  
Hardened State ◽  
3D Printed ◽  
Shape Retention ◽  
Interlayer Bond

This paper investigates the effect of polypropylene (PP) fibres on the fresh and hardened properties of 3D-printed fibre-reinforced geopolymer mortars. Different percentages of PP fibres ranging between 0.25% and 1.00% by volume were added to an optimised geopolymer mixture. All samples showed reasonable workability and extrudability. In addition, shape-retention ability in the fresh state was investigated as a major requirement for 3D-printing. The compressive strength of the printed specimens was tested in the hardened state in three loading directions, viz. longitudinal, perpendicular, and lateral. The flexural strength of samples was also tested in the longitudinal and lateral directions. In addition, the interlayer bond strength was investigated. Fibre addition seems to influence compressive strengths positively only when the loading is perpendicular to the interface plane. This is due to the preferential fibre alignment parallel to the direction of extrusion. The addition of fibre significantly enhanced the flexural performance of the printed samples. The use of fibre dosages of 0.75 and 1.00 vol % caused deflection-hardening behaviour of the 3D-printed geopolymers and, hence, a significantly higher fracture energy in comparison to specimens without fibre or with lower fibre content. However, an increase in the fibre volume caused some minor reduction in interlayer bond strength. With respect to properties in the fresh state, higher fibre volumes caused better shape-retention ability in the printed samples. The results indicate the possibility of printing fibre-reinforced geopolymers which meet all the necessary properties in both the fresh and hardened states.

scholarly journals Factors involved in the perceived risk of construction workers

DYNA ◽  
2015 ◽  
Vol 82 (192) ◽  
pp. 257-265
Author(s):  
Ignacio Rodríguez-Garzón ◽  
Myriam Martínez-Fiestas ◽  
Antonio Delgado-Padial ◽  
Valeriano Lucas-Ruiz
Keyword(s):  
Statistical Analysis ◽  
Perceived Risk ◽  
Exploratory Study ◽  
Classification Tree ◽  
Construction Workers ◽  
Important Predictor ◽  
Construction Sector ◽  
Catastrophic Risk ◽  
Psychometric Paradigm ◽  
Personal Vulnerability

This article is an exploratory study of perceived risk in the construction sector. We used a sample of 514 workers in Spain, Peru and Nicaragua. The method used was the psychometric paradigm and, under its assumptions we have studied nine factors or qualitative attributes of risk. The main statistical analysis was carried out using a classification tree. As a result is obtained that four of the nine attributes studied predict significantly the perceived risk of the sample. The attribute on the delay of the consequences has been the most important predictor in the model, followed by the attribute that explores the potential catastrophic risk and the attribute that explores the serious consequences. Finally the attribute related to the personal vulnerability has emerged. The implications of the results are exposed.

scholarly journals PROPRIEDADES DE ARGAMASSAS COM EVA (ETHYLENE VINYL ACETATE) EM SUBSTITUIÇÃO PARCIAL AO AGREGADO

2017 ◽  
Vol 13 (1) ◽  
Author(s):  
Cleidson Carneiro Guimarães ◽  
Érica Souza Andrade
Keyword(s):  
Vinyl Acetate ◽  
Industrial Waste ◽  
Raw Materials ◽  
Ethylene Vinyl Acetate ◽  
Project Managers ◽  
Partial Replacement ◽  
Construction Sector ◽  
Cement Ratio ◽  
Aggregate Content ◽  
Hardened State

RESUMO: O setor da construção civil apresenta grande potencial para aproveitamento de vários tipos de resíduos industriais. A incorporação dos resíduos, principalmente nas argamassas e concretos, produtos com vasta aplicabilidade no setor, tem se mostrado como uma ótima alternativa na diversificação das matérias-primas e para a economia de recursos naturais. Esse trabalho avaliou as propriedades das argamassas, no estado fresco e endurecido, produzidas com substituição parcial da areia por resíduo de EVA (Ethylene Vinyl Acetate). Para isso, foram preparadas argamassas com teores de substituição do agregado 0% (referência), 5%, 10% e 15%, em massa. A relação água/cimento, para cada traço, foi determinada empiricamente e mantida constante para as argamassas com substituição. Os resultados apontam que as argamassas produzidas com agregado de EVA apresentam menor absorção de água e também um decréscimo da resistência mecânica. Desta forma, a produção de argamassas utilizando EVA em substituição ao agregado natural é viável, todavia é necessário avaliar os parâmetros mínimos de aplicação para cada finalidade. Dessa forma, o trabalho apresenta contribuição ao servir de suporte a gestores de empresas de argamassas ou gestores de obra a tomarem decisões acerca da inserção do resíduo de EVA na produção de argamassa. ABSTRACT: The construction sector has great potential for use of various types of industrial waste. The incorporation of waste, especially in mortar and concrete products with wide applicability in the industry, has proven to be a great alternative for diversification of raw materials and the economy of natural resources. This study evaluated the properties of mortars in fresh and hardened state, made with partial replacement of sand by waste EVA (Ethylene Vinyl Acetate). For this, mortars were prepared with substitution aggregate content 0%(reference), 5%, 10% and 15% by weight. The water / cement ratio for each trace has been empirically determined and maintained constant for the mortars with replacement. The results show that the mortars produced with EVA aggregate have lower water absorption and also a decrease in the mechanical strength. Thus, the production of mortar using EVA instead of natural aggregate is feasible, however, it is necessary to evaluate the minimum parameters for each application purpose. Thus, the work presents contribution to provide support for the mortar company managers or project managers make decisions about the insertion of EVA residue in the production of mortar.

Evaluation of Mechanical Behavior and Microstructural Characteristics of Photocatalytic Concretes to Be Used as Pavement Blocks

2016 ◽  
Vol 138 (3) ◽  
Author(s):  
João Victor Staub de Melo ◽  
Glicério Trichês
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Mechanical Behavior ◽  
Tio2 Nanoparticles ◽  
Modulus Of Elasticity ◽  
Microstructural Characteristics ◽  
State Tests ◽  
Fresh State ◽  
Hardened State ◽  
Microstructural Behavior

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.

scholarly journals Experimental Study on Ready-Mix Concrete: Case Study

2018 ◽  
Vol 149 ◽  
pp. 01071
Author(s):  
Dorra Ellouze ◽  
Aida Ghammouri ◽  
Rahma Ben Amar
Keyword(s):  
Building Materials ◽  
Mechanical Tests ◽  
Professional Life ◽  
Price Ratio ◽  
Minimal Cost ◽  
Concrete Case ◽  
Fresh State ◽  
Hardened State ◽  
Ready Mix Concrete

Ready-mix concrete (RMC) in Tunisia is becoming more and more in demand in the civil engineering sector thanks to its qualities of handling in the fresh state and resistance in the hardened state, this composite material must respect the quality-price ratio. A RMC with a minimal cost is the object of our work. This research is part of the opening of higher education on professional life, where we optimized the formulation of a RMC. This work has 3 axes. In the first place the resources in building materials were characterized, namely various samples of sand, gravel, cement and water. Subsequently, the adjuvant-cement ratio (A/C) was optimized. Finally, the workability of the concrete as well as its mechanical aptitude at various ages 7, 14 and 28 days were characterized. These examinations have resulted in an appropriate formulation for any type of resource that varies according to the provenance of the quarries (gravel and sand), the effect of the plasticizer-water reducer is found for a very interesting A/C ratio, the mechanical tests for different ages are also conclusive.

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