scholarly journals CONSTITUTIVE MATERIAL MODEL FOR BLOCK MASONRY AND ITS MECHANICAL PROPERTIES

Author(s):  
Muhammad Junaid Iqbal

This research work aims at the development of a material model for concrete block masonry used in the load-bearing wall as well as masonry infill. To accomplish this, various tests were performed on concrete block (solid) units and concrete block masonry assemblage. A concrete block having a size of 12 x 8 x 6 inches, were fabricated in a mortar ratio of 1:4, 1:2:2, 1:8 and 1:4:4. The compressive strength of concrete block prisms having size 24.36 x 8.04 x 18.72 inches, was also determined by conducting the compressive strength test. The shear strength of square prisms, having size 26.76 x 8.04 x 25.20 inches, was found by applying diagonal loading. To investigate the bond shear strength of concrete block masonry, triplet tests were carried out on block masonry prisms. Before conduct, a test on block assemblage specimens, the constituent materials of block assemblage i.e. block and mortar were also tested for different properties. The average compressive strength of concrete block (12”x8”x6”) was 302.25 psi and the average unit weight was 119.83 lb/ft3. The compressive strength of mortars of 1:4, 1:2:2, 1:8 and 1:4:4 was 2367, 1752,815 and 1332 psi respectively.


Author(s):  
Muhammad Rizwan

This research work aims to investigate experimentally the mechanical properties of solid concrete blocks as an individual unit and assembly (block masonry) employing different mortar mix ratios. The material properties of the concrete block unit, such as compressive strength and unit weight were explored by taking three samples from the four local factories. The block masonry assemblages were subjected to various load patterns for the evaluation of compressive strength, diagonal tensile strength and shear strength. For the bond, four types of mortars i.e., cement – sand (1:4), cement – sand (1:8), cement – sand – khaka (1:2:2) and cement – sand – khaka (1:4:4) were used in the joints of concrete block masonry assemblages. (Khaka is a by-product formed in the stone crushing process). For each type of mortar, three samples of block masonry were fabricated for compressive strength, shear strength and diagonal tensile strength, and tested in the laboratory. It is observed that the replacement of sand by khaka enhanced the mechanical properties of masonry.



Author(s):  
Muhammad Arslan ◽  
Muhammad Asif Saleem ◽  
Maria Yaqub ◽  
Muhammad Saleem Khan

The focus of this research work was to analyse the effect of different types of curing oncompressive strength of concrete structures. For this purpose, 54 test specimens of cylindrical shape wereprepared. These specimens were cured with different methods and were tested on different age days toanalyse the effect of curing on compressive strength. Test specimens cured with conventional water curingmethod gives the highest results as compared to the other adopted methods.



Author(s):  
Archibong Ukeme Donatus ◽  
Ojeagah Kenneth ◽  
Michael Christopher Ukuegboho ◽  
I. E. Chiedu ◽  
Obasuyi Emmanuel Idemudia

This research work involved the preliminary studies of CaAl-LDHs using co precipitation method and applying it in the preparation of concrete to evaluate the compressive strength in grade 15 concrete. Slum and compressive strength test were carried out on the concrete control and concrete mixed with CaAl-LDH, Scanning electron microscope (SEM) and X-Ray Diffractogram (XRD) was carried out on the synthesize LDH, concrete control, and concrete mixed with LDH. From the results obtained in the work failure load test, it was observed that there was an increase by 62.60% in the compressive strength of concrete mixed with 30kg of CaAl-LDHs, the SEM micrograph also shows the increase in the density and the less porosity of the concrete mixed with CaAl-LDH which explained the increase in the compressive strength of the concrete. CaAl-LDH has therefore shows a promising effect on the increase on the compressive strength of concrete.



Author(s):  
Ananda Selvan

Abstract: A light weight concrete block using granulated corncob as an aggregate is investigated in this research work. Considering corn cob after removing the corn is said to be agricultural waste. Finding practical uses of this waste for manufacturing concrete block may preserve the environment and also allow green technologies. These concrete blocks are studied in terms of compressive strength, water absorption; density and unit weight were experimentally studied. The results obtained are submitted which shows that corn cob blocks have sufficient material properties for non-structural application in building for construction of partition walls. This is the alternative for blocks in expanded clay, expanded polystyrene, particles of cork, coconut coir etc. In this research a clay brick is compared as a reference block or control block. Nine specimen blocks were prepared in a size of 400mm x 200mm x 100mm and cured for 7 days, 14 days and 28 days and subjected to compressive strength test, water absorption test and density. The results are compared with conventional clay bricks. Corn cob blocks offered a good strength, low density and less water absorption. Keywords: Agricultural waste, compressive strength, durability, granulated corn



2018 ◽  
Vol 203 ◽  
pp. 06022
Author(s):  
Salmia Beddu ◽  
Daud Mohamad ◽  
Fadzli Mohamed Nazri ◽  
Siti Nabihah Sadon ◽  
Mohamed Galal Elshawesh

This study investigates the self-curing concrete using baby polymer diapers as substitute method of curing process in order to improve mechanical and physical properties of concrete. Three different proportion of baby polymer diapers which are 1%, 3% and 5% were mix with concrete. Slump, compressive strength and drying shrinkage test were performed in order to study the workability, strength and durability of the concrete. All concrete were tested for 1, 3, 7, 14, and 28 days for drying shrinkage test. Meanwhile, all concrete were test at 3, 7 and 28 days for compressive strength test. Compressive strength of concrete containing 5% baby polymer diapers show the highest strength at 28 days compared to others percentage. Thus, it indicates that application of baby polymer diaper as self-cure agent can improve the concrete performances.



2014 ◽  
Vol 2 (1) ◽  
pp. 75-82
Author(s):  
Elivs M. Mbadike ◽  
N.N Osadebe

In this research work, the effect of mound soil on concrete produced with river sand was investigated. A mixed proportion of 1.1.8:3.7 with water cement ratio of 0.47 were used. The percentage replacement of river sand with mound soil is 0%, 5%, 10%, 20%, 30% and 40%. Concrete cubes of 150mm x 150mm x150mm of river sand/mound soil were cast and cured at 3, 7, 28, 60 and 90 days respectively. At the end of each hydration period, the three cubes for each hydration period were crushed and their average compressive strength recorded. A total of ninety (90) concrete cubes were cast. The result of the compressive strength test for 5- 40% replacement of river sand with mound soil ranges from 24.00 -42.58N/mm2 a against 23.29-36.08N/mm2 for the control test (0% replacement).The workability of concrete produced with 5- 40% replacement of river sand with mound soil ranges from 47- 62mm as against 70mm for the control test.



2020 ◽  
Vol 2 (1) ◽  
pp. 31-57
Author(s):  
Ni Ketut Sri Astati Sukawati

Concrete with various variants is a basic requirement in building a building. The concrete mixture is diverse depending on the planning made beforehand. The cement mixture is usually in the form of a mixture of artificial stone, cement, water and fine aggregates and coarse aggregates. Aggregates (fine aggregates and coarse aggregates) function as fillers in concrete mixtures. (Subakti, A., 1994). However, in building construction, additives are often added, but there is still a sense of uncertainty at the time of dismantling the mold and the reference before the concrete reaches sufficient strength to carry its own weight and the carrying loads acting on it. To overcome the time of carrying out work related to concrete, it is necessary to find an alternative solution, for example by looking for alternative ingredients of concrete mixture on the basis of consideration without reducing the quality of the concrete. From the results of previous studies it was stated that due to the partial replacement of cement with Fly Ash, the strength of the pressure and tensile strength of the concrete had increased (Budhi Saputro, A., 2008). Based on the description above, the author seeks to examine how the compressive strength of concrete characteristics that occur by adding additives Addition H.E in the concrete mixture and is there any additive Additon H.E effect on the increase in the compressive strength characteristic of the concrete. From the results of the study, it was found that the compressive strength of the concrete with the addition of additives HE was that after the compressive strength test of the concrete cube was carried out and the analysis of concrete compressive strength of 10 specimens, in each experiment a cube specimen was made with the addition of additons. HE with a dose of 80 cc, 120 cc, and 200 cc can accelerate and increase the compressive strength of concrete characteristics.



2018 ◽  
Vol 34 ◽  
pp. 01006
Author(s):  
M. Mokhtar ◽  
M. Kaamin ◽  
S. Sahat ◽  
N.B. Hamid

The consumption of plastic has grown substantially all over the world in recent years and this has created huge quantities of plastic-based waste. Plastic waste is now a serious environmental threat to the modern way of living, although steps were taken to reduce its consumption. This creates substantial garbage every day, which is much unhealthy. Plastic bottles such as Polyethylene terephthalate (PET) was use as the partially component in this making of interlocking blocks concrete. This project investigates the strength and workability of the interlocking block concrete by replacing course aggregate with % PET. The suitability of recycled plastics (PET) as course aggregate in interlocking block concrete and its advantages are discussed here. Moreover, there were more benefits when using interlocking block than using conventional block such as it easy for construction because they are aligning, easy to place, high speed stacking and they offer more resistance to shear and buildings would be even stronger. Based on the test perform, the failure parameter were discussed .From the compressive strength test result, it shows that the strength of concrete block decreased with increased of PET used. From the results, it shows that higher compressive strength was found with 5% natural course aggregate replaced with PET compared to other percentages.



Author(s):  
Farhad Behnamfar ◽  
Hadi Rafizadeh ◽  
Mortza Omidi

This research work presents new details for moment connections in precast concrete structures satisfying both design and practice criteria. In this paper the results of the numerical study on the connections are presented. For the analysis, the ANSYS software is selected because of its diversity in nonlinear analysis. By calculating the monotonic load-displacement curve of each connection, the connections are evaluated for their stiffness, strength, and ductility. The compressive strength of the connection concrete is taken to be 30, 35 and 40 MPa, for each round of analysis. The results of the analysis show that the proposed connections are stiff enough to be moment resisting and to be emulating an equivalent monolithic, or basic connection. It is illustrated that the connections are stronger but somewhat less ductile than the basic connection regardless of the concrete strengths examined. Moreover, it is shown that in each precast connection while increasing the compressive strength of concrete does not affect the connection stiffness considerably, it increases the ultimate load and ductility of the connection. As a main result of this study, the suggested connection details are categorized based on their stiffness, strength, and ductility. The suggested connections can be used in moment resisting precast concrete buildings based on the desired strength and ductility.



Jurnal CIVILA ◽  
2021 ◽  
Vol 6 (2) ◽  
pp. 213
Author(s):  
Asrul Majid ◽  
Hammam Rofiqi Agustapraja

Infrastructure development is one of the important aspects of the progress of a country where most of the constituents of infrastructure are concrete. The most important constituent of concrete is cement because its function is to bind other concrete materials so that it can form a hard mass. The large number of developments using cement as a building material will leave quite a lot of cement bags.In this study, the authors conducted research on the effect of adding cement waste to the compressive strength of concrete. This study used an experimental method with a total of 24 test objects. The test object is in the form of a concrete cylinder with a diameter of 15 cm and a height of 30 cm and uses variations in the composition of the addition of cement waste cement as a substitute for fine aggregate, namely 0%, 2%, 4% and 6%. K200). The compressive strength test was carried out at the age of 7 days and 28 days.The test results show that the use of waste as a partial substitute for fine aggregate results in a decrease in the compressive strength of each mixture. at the age of 7 days the variation of 2% is 16.84 MPa, 4% is 11.32 MPa and for a mixture of 6% is 6.68 MPa. Meanwhile, the compressive strength test value of 28 days old concrete in each mixture decreased by ± 6 MPa. So the conclusion is cement cement waste cannot be used as a substitute for fine aggregate in fc 16.6 (K200) quality concrete because the value is lower than the specified minimum of 16.6 MPa.



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