scholarly journals Mechanical characterization of concrete block used on infill masonry panels

2018 ◽  
Vol 9 (3) ◽  
pp. 281-295 ◽  
Author(s):  
Patricia Raposo ◽  
André Furtado ◽  
António Arêde ◽  
Humberto Varum ◽  
Hugo Rodrigues

Purpose The infill masonry walls in recent worldwide earthquakes have shown that it is necessary to conduct further studies to characterize the behavior of existing buildings and, in particular, of infill masonry walls under seismic activity. The lack of characterization studies of infill walls made by concrete blocks justifies the investigation reported herein, which includes experimental tests on sample sets to evaluate the mechanical properties of masonry components (units and mortar) and assemblages (wallets) made with masonry units from Faial. For the later, normal compressive, diagonal tensile/shear and out-of-plane flexural strengths were obtained according to standard procedures, the results of which are presented in the manuscript. The paper aims to discuss these issues. Design/methodology/approach One experimental campaign was conducted with the aim to mechanically characterize concrete blocks masonry samples. Several experimental tests were carried out in full-scale masonry concrete wallets according to the constructive methodology used. Findings Based on the data obtained from the mechanical characterization tests of the concrete masonry blocks, it can be seen that under simple compression, the masonry specimens’ average resistance is about 6 times superior than the average resistance to diagonal shear/tension, while the stiffness is almost doubled. In simple compression tests, it was observed that the masonry specimens cracked in areas of higher drilling of the blocks. In the tensile tests by diagonal compression, it was found that the test specimens were mainly fissured by the block/mortar joint interfaces, following the delineation of settlement and top joints. Originality/value There are no experimental results available in the literature for this type of bricks that can contribute to the development of numerical studies.

2021 ◽  
Vol 881 ◽  
pp. 149-156
Author(s):  
Mochamad Teguh ◽  
Novi Rahmayanti ◽  
Zakki Rizal

Building material innovations in various interlocking concrete block masonry from local materials to withstand lateral earthquake forces is an exciting issue in masonry wall research. The block hook has an advantage in the interlocking system's invention to withstand loads in the in-plane and out-of-plane orientations commonly required by the masonry walls against earthquake forces. Reviews of the investigation of in-plane and out-of-plane masonry walls have rarely been found in previous studies. In this paper, the results of a series of experimental tests with different interlocking models in resisting the simultaneous in-plane shear and out-of-plane bending actions on concrete blocks are presented. This paper presents a research investigation of various interlocking concrete blocks' mechanical properties with different hook thicknesses. Discussion of the trends mentioned above and their implications towards interlocking concrete block mechanical properties is provided.


2017 ◽  
Vol 17 (3) ◽  
pp. 25-37
Author(s):  
Luciane Marcela Filizola de Oliveira ◽  
Márcio Roberto Silva Corrêa

Abstract Predicting the behavior of interconnected masonry walls is a challenging issue, given the influence of a wide range of factors, such as the mechanical properties of the materials (blocks and mortar) and the way the walls are connected to each other. In this paper, experimental results in H-shaped walls subjected to shear at the vertical interface are introduced with a numerical representation. Concrete blocks and two types of connections (running bond and U-steel anchors) were considered in the tests. Computational modelling was carried out using the Diana® FEM software to complete the study and understand the structural behavior of the masonry panels. The influence of the bonding pattern on the experimental and numerical response was studied and good agreement between the results was found. Moreover, the numerical analysis showed that the computer models of the interconnected walls adequately represented the behavior of the physical models regarding load capacity and cracking patterns.


2016 ◽  
Vol 16 (4) ◽  
pp. 526-544 ◽  
Author(s):  
Salvador Noriega Morales ◽  
Adán Valles Ch. ◽  
Vianey Torres-Argüelles ◽  
Erwin Martínez G. ◽  
Andrés Hernández G.

Purpose This paper aims to describe the application of several Six Sigma tools to explain the improvement changes needed in a company that manufactures concrete blocks. The paper explains the methodology and the tools of the Six Sigma system, their use in the project, the application of the DMAIC (Define, Measure, Analyse, Improve and Control) process for the identification and definition of the problems, the related performance variables and the results obtained. Design/methodology/approach The paper reports the research made to improve the production of concrete blocks, specifically, the application of the DMAIC process, which is part of the Six Sigma methodologies; DMAIC stands for Definition of the problem, Measurement of the performance, Analysis using specific statistical methods and tools, Improvement the factors that cause the problem and Control the processes to ensure that the problem will not occur again. Each of those steps is explained in detail in the paper, which also presents the application of other improvement techniques. Findings The results show the adaptability and relevance of Six Sigma for the improvement of production operations. It is clearly demonstrated that it leads to benefits such as the elimination of machine downtime, reduction of scrap from 18 to 2 per cent and the improvements made in plant layout and production facilities to increase the productivity. Research limitations/implications In improvement projects, the differential between the initial and final conditions varies, depending on the magnitude of the problems or potential opportunities. Although this paper describes only the application of Six Sigma, the methodology has a wide potential application in most manufacturing industries. Practical implications With the Six Sigma and DMAIC tools’ application and the improvement process, the agility obtained is driving a more mechanized perspective of production operations. The customer service level was increased, through fast deliveries of complete orders. This project shows that the application of the Six Sigma methodology is feasible and produces attractive financial and operational results in this segment of the construction industry. Originality/value The companies dedicated to the production of concrete blocks commonly reproduce the systems and standards of the industry, which are commonly designed around civil engineering and technical issues. Thus, the application of improvement tools is exceptional in manufacturing environments. Although this paper is just one application of the methodology, it explains in detail the DMAIC use for companies that are committed to the development of new competencies to increase their competitiveness.


2019 ◽  
Vol 817 ◽  
pp. 435-441 ◽  
Author(s):  
Jacopo Donnini ◽  
Gianluca Maracchini ◽  
Gianluca Chiappini ◽  
Valeria Corinaldesi ◽  
Enrico Quagliarini ◽  
...  

The use of Textile Reinforced Mortar (TRM) systems represent a valid alternative to traditional strengthening techniques, to improve mechanical strength and seismic performance of masonry buildings. Their effectiveness has been validated by several studies [1-4]. However, the TRM contribution in the mechanical behavior of masonry walls, subjected to simple compression, has not yet been fully investigated. In this study, an experimental campaign with the objective of studying the efficiency of TRM systems, applied to clay brick masonry panels, is presented. Compression tests were conducted on clay brick masonry panels with dimensions of 250x1000x1200 mm3. Glass fiber bidirectional fabrics were applied on both sides of the panels, coupled with lime-based mortar, and connected with stainless steel helical connectors. The total thickness of the reinforcement system is 30 mm. The effect of the TRM reinforcement on the mechanical behavior of the panel is analyzed and experimental results are compared with those of unreinforced panels in terms of ultimate strength and failure modes.


2014 ◽  
Vol 941-944 ◽  
pp. 786-799 ◽  
Author(s):  
G. I. Grinfeld ◽  
Alexsandr S. Gorshkov ◽  
Nikolay I. Vatin

This article deals with the strength and thermophysical test results made on the basis of the masonry samples of cellular autoclave curing concrete (aerated concrete blocks) with the use of polyurethane adhesive. Aerated concrete masonry walling with the use of polyurethane adhesive is indicated herein to be technologically feasible and economically viable. The major advantage of the masonry option under consideration lies in the following aspect: thermal conductivity of polyurethane adhesive used to fasten aerated concrete blocks in masonry walls is significantly less than thermal conductivity of concrete adhesives and mortars. For this reason, thermal insulation properties of the masonry with polyurethane adhesive appear to be better comparatively to the block masonry made with the usage of concrete adhesives of any other type. On the ground of the tests conducted the following was resumed: it is acceptable to carry out masonry works with the use of aerated concrete blocks and polyurethane adhesive in construction of exterior and interior nonbearing walls provided appropriate justifying calculations are made.


Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4174
Author(s):  
André M. Santos ◽  
Ângelo J. Costa e Silva ◽  
João M. F. Mota ◽  
João M. P. Q. Delgado ◽  
Fernando A. N. Silva ◽  
...  

The understanding of the mechanical fixation behavior of coatings is crucial for a better comprehension of the bonding systems, especially at the interface between the mortar and the substrate. Physical adherence is related, among other things, to the contents of the materials used in the roughcast and mortar coatings, due to the colloidal water penetration into the pores of the substrate. This work evaluated the influence of different lime solution additions replacing the kneading water in the preparation of roughcast and mortar coatings. Two types of substrates were investigated:ceramic bricks and concrete blocks. Three wall masonry panels were constructed, with dimensions of 220 × 180 cm2, one of concrete block and two of ceramic bricks, followed by the application of roughcast and mortar coating with an average thickness of 5 mm and 20 mm, respectively. Direct tensile bond strength tests were performed and the results, with a 95% confidence level, showed that substrate ceramic and treatment in the roughcast exhibited a better behavior regarding the distribution of the tensile bond strength of the tested specimens. However, no significant differences of the amount of addition used (0%, 5%, 10% and 15%) on the tensile bond strength were observed.


2021 ◽  
Vol 11 (11) ◽  
pp. 5008
Author(s):  
Juan José del Coz-Díaz ◽  
Felipe Pedro Álvarez-Rabanal ◽  
Mar Alonso-Martínez ◽  
Juan Enrique Martínez-Martínez

The thermal inertia properties of construction elements have gained a great deal of importance in building design over the last few years. Many investigations have shown that this is the key factor to improve energy efficiency and obtain optimal comfort conditions in buildings. However, experimental tests are expensive and time consuming and the development of new products requires shorter analysis times. In this sense, the goal of this research is to analyze the thermal behavior of a wall made up of lightweight concrete blocks covered with layers of insulating materials in steady- and transient-state conditions. For this, numerical and experimental studies were done, taking outdoor temperature and relative humidity as a function of time into account. Furthermore, multi-criteria optimization based on the design of the experimental methodology is used to minimize errors in thermal material properties and to understand the main parameters that influence the numerical simulation of thermal inertia. Numerical Finite Element Models (FEM) will take conduction, convection and radiation phenomena in the recesses of lightweight concrete blocks into account, as well as the film conditions established in the UNE-EN ISO 6946 standard. Finally, the numerical ISO-13786 standard and the experimental results are compared in terms of wall thermal transmittance, thermal flux, and temperature evolution, as well as the dynamic thermal inertia parameters, showing a good agreement in some cases, allowing builders, architects, and engineers to develop new construction elements in a short time with the new proposed methodology.


2014 ◽  
Vol 11 (03) ◽  
pp. 1343002 ◽  
Author(s):  
GIULIO MAIER ◽  
VLADIMIR BULJAK ◽  
TOMASZ GARBOWSKI ◽  
GIUSEPPE COCCHETTI ◽  
GIORGIO NOVATI

A survey is presented herein of some recent research contributions to the methodology of inverse structural analysis based on statical tests for diagnosis of possibly damaged structures and for mechanical characterization of materials in diverse industrial environments. The following issues are briefly considered: identifications of parameters in material models and of residual stresses on the basis of indentation experiments; mechanical characterization of free-foils and laminates by cruciform and compression tests and digital image correlation measurements; diagnosis, both superficially and in depth, of concrete dams, possibly affected by alkali-silica-reaction or otherwise damaged.


2016 ◽  
Vol 711 ◽  
pp. 982-988
Author(s):  
Alex Brodsky ◽  
David Z. Yankelevsky

Numerous studies have been conducted on the in plane behavior of masonry infill walls to lateral loading simulating earthquake action on buildings. The present study is focused on a problem that has almost not been studied regarding the vertical (opposed to lateral) in-plane action on these walls. This may be of concern when a supporting column of a multi-storey reinforced concrete frame with infill masonry walls undergoes a severe damage due to an extreme loading such as a strong earthquake, car impact or military or terror action in proximity to the column. The loss of the supporting column may cause a fully or partly progressive collapse to a bare reinforced concrete frame, without infill masonry walls. The presence of the infill masonry walls may restrain the process and prevent the development of a progressive collapse. The aim of the present study is to test the in-plane composite action of Reinforced Concrete (RC) frames with infill masonry walls under vertical loading through laboratory experiments and evaluate the contributions of infill masonry walls, in an attempt to examine the infill masonry wall added resistance to the bare frame under these circumstances. Preliminary results of laboratory tests that have been conducted on reinforced concrete infilled frames without a support at their end, under monotonic vertical loading along that column axis will be presented. The observed damages and failure modes under vertical loading are clearly different from the already known failure modes observed in the case of lateral loading.


2017 ◽  
Vol 10 (2) ◽  
pp. 477-508 ◽  
Author(s):  
C. F.R. SANTOS ◽  
R. C. S. S. ALVARENGA ◽  
J. C. L. RIBEIRO ◽  
L. O CASTRO ◽  
R. M. SILVA ◽  
...  

Abstract This work developed experimental tests and numerical models able to represent the mechanical behavior of prisms made of ordinary and high strength concrete blocks. Experimental tests of prisms were performed and a detailed micro-modeling strategy was adopted for numerical analysis. In this modeling technique, each material (block and mortar) was represented by its own mechanical properties. The validation of numerical models was based on experimental results. It was found that the obtained numerical values of compressive strength and modulus of elasticity differ by 5% from the experimentally observed values. Moreover, mechanisms responsible for the rupture of the prisms were evaluated and compared to the behaviors observed in the tests and those described in the literature. Through experimental results it is possible to conclude that the numerical models have been able to represent both the mechanical properties and the mechanisms responsible for failure.


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