scholarly journals Analysis and validation of correlation curves between sclerometry and compression tests for the evaluation of compressive strength of concretes

2018 ◽  
Vol 11 (4) ◽  
pp. 779-809
Author(s):  
T. M. OLIVEIRA ◽  
M. C. R. FARAGE ◽  
L. GOLIATT ◽  
T. C. BITTENCOURT

Abstract The present work consists in obtaining correlation curves between compressive tests and sclerometry tests from an extensive experimental program comprising 630 concrete cylindrical samples cast in laboratory, employing materials and methods available in Brazil. The concretes, with compressive strengths ranging from 20~MPa to 50~MPa, were submitted to sclerometry tests and mechanical compressive tests. The results were used to obtain correlation curves. which were adopted in measurements of structural elements molded in a construction site, indicating that the curves provided by the equipment manufacturer are not suitable for the material in study. This is the first stage of a broader study aiming to contribute to the improvement of the Brazilian code regulating the application of the sclerometry to obtain concrete compressive strength.

2014 ◽  
Vol 894 ◽  
pp. 45-49 ◽  
Author(s):  
Luisa Pani ◽  
Lorena Francesconi

In this paper an experimental program has been carried out in order to compare compressive strength fcand elastic static modulus Ecof recycled concrete with ultrasonic waves velocity Vp, to establish the possibility of employing nondestructive ultrasonic tests to qualify recycled concrete. 9 mix of concrete with different substitution percentage of recycled aggregates instead of natural ones and 27 cylindrical samples have been made. At first ultrasonic tests have been carried out on cylindrical samples, later elastic static modulus Ecand compressive strength fchave been experimentally evaluated. The dynamic elastic modulus Edhas been determined in function of ultrasonic wave velocity Vp; furthermore the correlations among Ed, Ec, fce Vphave been determined. It has been demonstrated that ultrasonic tests are suitable for evaluating different deformative and resisting concrete performances even when variations are small.


Author(s):  
Cesar Ponce Palafox ◽  
Julián Carrillo ◽  
Areli López-Montelongo

Resumen La industria del mármol genera gran cantidad de desperdicio en polvo. Estos desechos carecen de un adecuado plan de manejo, además de resultar altamente contaminantes a la población que rodea el lugar de los depósitos de estos materiales. Para ofrecer una solución, en este artículo se presentan los resultados del desarrollo de un ladrillo a base del polvo de mármol. El programa experimental incluye 16 dosificaciones diferentes en las que se varía la cantidad de cemento, cal y arena, y se deja constante el polvo de mármol. El programa incluye el ensayo a compresión de 160 ladrillos, 3 ensayos a compresión en muretes, 3 pruebas de adherencia a compresión en muretes y 48 pruebas de absorción.  Los resultados de compresión y adherencia demostraron que estos ladrillos podrían ser utilizados para la construcción de muros de carga en vivienda desarrolladas en zonas de amenaza sísmica baja. Palabras clave:  Absorción; adherencia; compresión; muros de carga; vivienda   Abstract The marble industry generates large amount of dust waste. These wastes do not have a proper management plan, as well as being highly contaminating the population surrounding the site of the deposits of these materials. To offer a solution, this article shows the results of the development of a brick-based marble powder to achieve sufficient compressive strength to construction masonry walls in low-rise housing. The experimental program includes 16 different dosages that varies the amount of cement, lime, and sand, and keeping constant the marble powder. The program includes the compressive tests for 160 bricks, compressive tests for 3 small walls, validated adherence under compression tests for 3 small walls, and absorption tests for 48 bricks. The results of the test showed that the compression strength of the individual bricks and wall is 4.0 MPa y 1.9 MPa, respectively, and the absorption of the bricks es 21 %. This results of absorption , compression and adhesion are a first indication of the feasibility of used  these bricks for the construction of load-bearing walls in housing developed in areas of low seismic demands. Key Words: Absorption; adhesion; compression; load-bearing walls; housing


2021 ◽  
Vol 318 ◽  
pp. 03004
Author(s):  
AbdulMuttalib I. Said ◽  
Baqer Abdul Hussein Ali

This paper has carried out an experimental program to establish a relatively accurate relation between the ultrasonic pulse velocity (UPV) and the concrete compressive strength. The program involved testing concrete cubes of (100) mm and prisms of (100×100×300) cast with specified test variables. The samples are tested by using ultrasonic test equipment with two methods, direct ultrasonic pulse (DUPV) and surface (indirect) ultrasonic pulse (SUPV) for each sample. The obtained results were used as input data in the statistical program (SPSS) to predict the best equation representing the relation between the compressive strength and the ultrasonic pulse velocity. In this research 383 specimens were tested, and an exponential equation is proposed for this purpose. The statistical program has been used to prove which type of UPV is more suitable, the (SUPV) test or the (DUPV) test, to represent the relation between the ultrasonic pulse velocity and the concrete compressive strength. In this paper, the effect of salt content on the connection between the ultrasonic pulse velocity and the concrete compressive strength has also been studied.


2020 ◽  
Vol 13 (1) ◽  
pp. 45-53
Author(s):  
Sajid Kamil Zemam

This study seeks to develop a sustainable construction technique based on the introduction of a specific method for improving concrete compressive strength through a proposed multi-vibration compaction method. An experimental program is performed to evaluate the effect of the proposed compaction technique on fresh silica fume concrete undergoing the initial setting. Multi-vibration intends to minimize concrete production cost because it upgrades the compressive strength of the same materials with better utilization of the vibration energy required for compaction. The collected experimental data presented assign relationships among vibration duration, vibration cycles or phases, and compressive strength upgrading of single vibrated, revibrated, and multi-vibrated specimens for analysis and discussion. This study shows that multi-vibration phases, rather than single vibration or revibration techniques, are powerful techniques for improving concrete compressive strength. The results indicated that the existence of an optimum multi-vibration mode was dominated by phase number and vibration duration and confirm the reliability vibration overall time duration recommended by ACI 309 which relates to a single vibration time limit to be considered in the case of multi vibration technique. Multi-vibration Mode 8 (subjected to three vibration phases 10, 20, and 30 sec ) has the best effect for the considered mixtures among the specific vibration modes. The maximum improvement ratio is 1.25, which is associated with the plastic mixture.   


Author(s):  
Ahmad Salah Edeen Nassef ◽  
Kalifa Hamed AlMuqbali ◽  
Sheikha Mahmood Al Naqabi

This paper was studying the effects of palm tree wastes on the behavior of the concrete to reduce cement content in the concrete to ensure a sustainable environment. Both fibers of palm tree and the ash of palm tree leaves are used in this study considering different percentages of palm tree wastes, which are replaced the cement, to investigate both of workability and strength of the concrete. Also, the combination of palm tree leaves ash and fibers of palm trees is investigated. The slump and compression tests are carried out to evaluate both workability and concrete strength. The palm fibers were reducing the workability of concrete at both of different percentage of replacement and different fiber lengths. The slump is reduced by 26.667% at 2 cm fibers length and it is completely lost at 5 cm length fibers at the same percentage of replacement of 5% of the cement content. The palm fibers were weakening concrete compressive strength at different percentages and different fiber lengths. Palm leaves ash was enhancing concrete workability and concrete compressive strength.


2012 ◽  
Vol 174-177 ◽  
pp. 1584-1588 ◽  
Author(s):  
Ning Hui Liang ◽  
Xin Rong Liu ◽  
Ji Sun

Through compression tests on 30 plain concrete and polypropylene fiber concrete specimens with the dimensions of 100mm × 100mm × 100mm , studied the influence of the different scales of polypropylene fiber and hybrid fiber on concrete compressive strength and compressive deformation. The results showed that: the compressive strength of concrete for single-doped fiber has little effect to improve concrete compressive strength, some even get lower,but mixing-doped coarse-fine fiber had increased 6.2%~13.7%. Doped-fiber can improve the concrete compressive toughness, it's enhancement sort: mixing-doped coarse-fine fiber concrete > single-doped coarse fiber concrete > single-doped fine fiber concrete> plain concrete


2013 ◽  
Vol 671-674 ◽  
pp. 1813-1816
Author(s):  
Xiang Hao Wu ◽  
Yong Xin Yao ◽  
Xing Wei Yin ◽  
Pan Yuan

The influence of part of fly ash replaced with lime dust on fly ash recycle concrete compressive strength and frost resistance is investigated by compression tests and rapid frost-thawing test. The experimental results show that part of fly ash replaced with lime dust will reduce the early compressive strength of the fly ash recycled concrete; the right amount of lime dust replacing fly ash can raise the latter compressive strength of fly ash recycled concrete, the best replacement proportion is 10%. The anti-frozen capacity of fly ash recycled concrete will reduce by replacing part of fly ash with lime dust, and the amplitude reduction of anti-frozen capacity of fly ash recycled concrete in seawater is greater than the amplitude reduction in sulfate solution and in freshwater.


2021 ◽  
Author(s):  
Mariella Diaferio ◽  
Michele Vitti

Abstract During the recent decades, the use of non-destructive tests has reached greater attention due to its high versatility and the possibility of extending the investigations on a great number of points. On the other side, the existence of a wide building stock realized in reinforced concrete, which is reaching the end of its service life, has increased the research on the assessment of their safety level. In this field, one of the most important parameters for r.c. structure is the concrete compressive strength, which “classically” is evaluated by means of compression tests on drilled cores. However, usually the extension of such procedure to a high number of points is quite difficult due to logistic and economic reasons. The use of non-destructive tests may overcome these limits, but still needs further investigations to improve the calibration process of the relationship between the acquired data and the compressive strength. The present paper deals with this issue and discusses the results of the investigations on r.c. buildings in Bari (Italy) which make use of both destructive and non-destructive tests. The data are analyzed by considering several test scenarios and by evaluating the variability of parameters related to the calibration process.


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