scholarly journals Determination of Mortar Strength in Historical Brick Masonry Using the Penetrometer Test and Double Punch Test

Materials ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 2873 ◽  
Author(s):  
Dawid Łątka ◽  
Piotr Matysek
Keyword(s):  
Compressive Strength ◽  
Laboratory Tests ◽  
Test Method ◽  
Specimen Thickness ◽  
Test Results ◽  
Punch Test ◽  
Mortar Strength ◽  
Surface Disturbance ◽  
Historical Masonry

This paper presents the results of the minor destructive testing of mortars in masonry structures of four buildings erected at the turn of the 19th and 20th centuries. The buildings were erected in the historical centre of Cracow. The objective of testing was to determine mortar compressive strength in masonry joints. The in situ tests were carried out with the use of a penetrometer RSM-15 with the standardised impact energy equalling 4.55 nm. Laboratory tests on mortar specimens taken from the structures were also performed. The double punch test method was used in the laboratory tests. On account of the specificity of the tested historical mortars, the typical procedures used in penetrometer and double punch tests were modified. For penetrometer tests, a new feature called “a surface disturbance zone” was introduced. Additionally, a procedure for determining a surface disturbance zone range was included. As confirmed in the paper, the consideration of the surface disturbance zone in the analysis of test results is crucial for the correct evaluation of mortar compressive strength. The thicknesses of bed joints in the tested historical masonry considerably exceeded the requirements included in the standard EN 1996-1-1. Thus, the thickness of the mortar specimens taken from historical masonry for the double punch tests clearly exceeded the thickness of specimens extracted from the typical structures erected nowadays. This article provides a method of considering a specimen thickness parameter in the analysis of double punch test results. The in situ test results with the use of penetrometer and double punch methods confirmed that the mortar strength in tested historical buildings ranged from 1.4 to 2.9 MPa. Mortar compressive strength values determined by both applied methods were similar.

scholarly journals Orthogonal Analysis on Mechanical Properties of Basalt–Polypropylene Fiber Mortar

Materials ◽  
2020 ◽  
Vol 13 (13) ◽  
pp. 2937
Author(s):  
Huimin Chen ◽  
Chunyan Xie ◽  
Chao Fu ◽  
Jing Liu ◽  
Xiuli Wei ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Flexural Strength ◽  
Volume Content ◽  
Fiber Length ◽  
Content Volume ◽  
Polypropylene Fiber ◽  
Basalt Fiber ◽  
Test Method ◽  
Test Results ◽  
Fiber Volume

Orthogonal test method was applied to analyze the strength properties of basalt-polypropylene mortar. The effect of basalt fiber length, polypropylene fiber length, basalt fiber volume content and polypropylene fiber volume content on the 28 d cube compressive strength and flexural strength were investigated. Test results show that comparing with flexural strength, the influence of basalt fiber length and polypropylene fiber length on compressive strength of mortar was greater than on flexural strength. The length of polypropylene fibers contributes the highest to the flexural strength. The effect of basalt fiber on mortar strength is the largest with 6 mm length and 4% content. Polypropylene fiber length has the greatest influence on the compressive strength of fiber mortar, followed by basalt fiber volume content. Volume content of polypropylene fiber has the greatest influence on flexural strength of fiber mortar, followed by polypropylene fiber length. According to the scoring of the efficacy coefficient method, the best ratio combination for compressive and flexural strength was the basalt fiber length of 9 mm, polypropylene fiber length of 6 mm, basalt fiber volume content of 4% and polypropylene fiber volume content of 4%. Compared with the blank samples, the 28 d compressive strength and 28 d flexural strength of the cement mortar samples were increased by 27.4% and 49% respectively. According to the test results, the properties of the fiber were analyzed and evaluated and the mechanism of fiber action and fiber microstructure were analyzed.

Assessment of the Concrete Compressive Strength in Existing Structures Based on Core Test Results

2018 ◽  
Vol 272 ◽  
pp. 238-243 ◽  
Author(s):  
Viktar V. Tur ◽  
Stanislav S. Derechennik
Keyword(s):  
Monte Carlo Simulation ◽  
Quality Control ◽  
Compressive Strength ◽  
Structural Reliability ◽  
Reliability Estimation ◽  
Control Procedure ◽  
Test Results ◽  
Concrete Compressive Strength ◽  
Existing Structures

Evaluation of the concrete compressive strength in existing structures is an important problem, which is associated with structural reliability estimation as well as a quality control procedure. In accordance with a new concept of EN 13791, reported by T.A.Harrison, one of the main targets of the standard is to determine not a class, but in-situ characteristic concrete compressive strength. Hereby proposed criterion for the estimation of the in-situ characteristic concrete compressive strength is based on the non-parametric confidence interval for quantile. This criterion was verified by the both Monte Carlo simulation and test results under the real concrete structures.

Study on the Compressive Strength and Mixing of Ultra-High Performance Concrete

2013 ◽  
Vol 357-360 ◽  
pp. 825-828
Author(s):  
Su Li Feng ◽  
Peng Zhao
Keyword(s):  
Compressive Strength ◽  
High Performance ◽  
High Performance Concrete ◽  
High Strength ◽  
Strength Properties ◽  
Test Method ◽  
Test Results ◽  
Concrete Compressive Strength ◽  
Ultra High Performance Concrete ◽  
Mixture Ratio

The test in order to obtain liquidity, higher intensity ultra-high performance concrete(UHPC), in the course of preparation, high intensity quartz sand to replace the ordinary sand,reasonable mixture ratio control low water-cement ratio,the incorporation of part of the test piece ofsteel fibers, produced eight specimens . In the ordinary molding and the standard conservation 28d thecase, the ultra-high-performance concrete compressive strength of more than 170MPa.Thepreparation of the test method and test results will provide the basis for further study of the law of themechanical properties of ultra high strength properties of concrete.

scholarly journals A Qualitative Study of Thermochemical Degradation Related with Concrete and Mortar Strength

2015 ◽  
Vol 2015 ◽  
pp. 1-7
Author(s):  
José Mora-Ruacho ◽  
Humberto A. Monreal-Romero
Keyword(s):  
Compressive Strength ◽  
Thermal Equilibrium ◽  
Laboratory Tests ◽  
Qualitative Method ◽  
Calcium Content ◽  
Mortar Strength ◽  
Reported Study ◽  
Compressive Strength Of Concrete ◽  
Best Parameter ◽  
Thermochemical Reaction

The nondestructive methods applied to the evaluation of concrete use different parameters to be related in the estimated resistance of concrete or other properties. The conducted study has evaluated a qualitative method of thermochemical degradation in concrete and mortar using a solvent acid whose chemical energy is capable of degrading the material. The reported study consisted in performing laboratory tests on mechanical compressive strength of concrete and mortar and thermochemical tests performed on little cores of concrete or mortar immersed in hydrochloric acid contained in a calorimeter system, obtaining several parameters as the time of thermal equilibrium, increase of temperature, degradation energy, and mass loss due to the thermochemical reaction. From the obtained results, these variables were analyzed and served as a parameter to be related with the concrete or mortar strength. The best parameter proved to be a good estimator was the increase of temperature and its degradation energy, whose value was inversely proportional to the strength of the material. Also, it is found that the most significant mechanisms that influenced the thermochemical reaction are the calcium content and the water chemically bound in the cement paste to perform the thermochemical test.

scholarly journals Effect of Carbonation on Abrasion Resistance of Alkali-Activated Slag with Various Activators

Materials ◽  
2019 ◽  
Vol 12 (17) ◽  
pp. 2812 ◽  
Author(s):  
Hyeong-Ki Kim ◽  
Keum-Il Song ◽  
Jin-Kyu Song ◽  
Jeong Gook Jang
Keyword(s):  
Compressive Strength ◽  
Abrasion Resistance ◽  
Test Method ◽  
Test Results ◽  
Alkali Activated Slag ◽  
Matrix Strength ◽  
Before And After ◽  
Activated Slag ◽  
The Relationship ◽  
Alkali Activated

The effect of carbonation on the abrasion resistance of alkali-activated slag (AAS) was investigated. Various activator sets were selected for synthesizing AAS specimens, and the compressive strength was measured before and after carbonation. The abrasion resistance of the specimens was measured in accordance with the ASTM C944 test method. The relationship between the mass loss caused by abrasion and compressive strength was analyzed to understand the effect of matrix strength on abrasion resistance. Test results showed that the decrease in compressive strength of AAS specimens by carbonation reduced their abrasion resistance. In addition, the abrasion resistance of AAS before and after carbonation was sensitively influenced by activator type. It can be concluded that additional caution is required when using AAS where abrasion may have occurred.

Size Effect of Concrete Compressive Strength with Different Aggregate Composition

2008 ◽  
Vol 400-402 ◽  
pp. 831-835 ◽  
Author(s):  
Jie Su ◽  
Zuan Yang ◽  
Zhi Fang
Keyword(s):  
Compressive Strength ◽  
Size Effect ◽  
Axial Compression ◽  
Axial Load ◽  
Test Method ◽  
Test Results ◽  
Concrete Compressive Strength ◽  
Concrete Prism ◽  
Compressive Strength Of Concrete ◽  
Aggregate Composition

81 concrete prism specimens under axial compression were tested to invesgigate the size effect on the axial load stength. Three different kinds of specimens with the dimension 100×100×300mm, 150×150×300mm, 200×200×400mm were tested. The parameters including compressive strength of concrete and aggregate composition are taken into consideration. Three different strength grades of concrete and three different aggregate composition are included in those specimens. The test method are undertaken according to ASTM C 39/C 39M-2005. Based on the test results, a new size effect law for different kinds of concrete in prismatical compressive strength is suggested and those relative parameters on the size effect are discussed.

scholarly journals In-Situ and Laboratory Investigation on Leaching and Effects of Early Curing of Shotcrete

2019 ◽  
Vol 61 (2) ◽  
pp. 23-37
Author(s):  
Andreas Sjölander ◽  
Anders Ansell
Keyword(s):  
Water Pressure ◽  
Test Method ◽  
Test Results ◽  
Water Penetration ◽  
Sprayed Concrete ◽  
Future Studies ◽  
One Year ◽  
Rock Tunnel ◽  
Short Time

Abstract During the construction of a rock tunnel in Stockholm, several sections with leaching shotcrete (sprayed concrete) were found one year after the spraying was completed. An investigation was therefore conducted, and its results are presented in this paper. The amount of leaching after such a short time indicated that a one-sided water pressure existed in combination with a permeable shotcrete. The reason for the water pressure was likely a partly unsuccessful grouting that created sections with leaking water. The permeable shotcrete could be a combined result of insufficient curing and the use of accelerators, and the effect of in-situ curing was therefore investigated. A total of six slabs were sprayed and cured under different conditions in the tunnel. Test results according to standards indicated that curing has no significant effect on the development of mechanical strength or water penetration through the shotcrete. However, this is believed to be a result of the test method rather than the non-existing effect of curing. Lastly, some modifications to the test standard were proposed for future studies of in-situ curing.

Applicatons of Hydration Thermodynamics to In-Situ Test Results

1993 ◽  
Vol 333 ◽  
Author(s):  
M. J. Plodinec ◽  
G. G. Wicks
Keyword(s):  
Laboratory Tests ◽  
Glass Production ◽  
Natural Environments ◽  
Test Results ◽  
In Situ Tests ◽  
Important Conclusion ◽  
In Situ Test ◽  
Long Term Performance ◽  
Term Performance

ABSTRACTAn extremely important question for the eventual disposal of glass in natural environments is the relevance of laboratory testing of glass durability to the long-term performance of glass in geologic environments. The purpose of this study was to attempt to provide an empirical answer to that question, by applying the hydration thermodynamics approach (which has successfully been applied to laboratory tests of glass durability) to the results of longer-term testing in natural environments.The results show that hydration thermodynamics is a useful tool for explaining the effects of glass composition observed in in-situ tests, in several environments. Thus, it appears to provide a link between laboratory tests of glass durability and the results of in-situ tests in natural environments. Perhaps the most important conclusion of this effort is that the in-situ test results emphasize the importance of control of chemical composition during glass production as a means of achieving a durable glass.

scholarly journals Dowel Behavior of Rebars in Small Concrete Block for Sliding Slab Track on Railway Bridges

2018 ◽  
Vol 2018 ◽  
pp. 1-15 ◽  
Author(s):  
Seong-Cheol Lee ◽  
Sangmin Park ◽  
Jaeha Lee ◽  
Kyoung-Chan Lee
Keyword(s):  
Compressive Strength ◽  
Concrete Block ◽  
Shear Capacity ◽  
Specimen Thickness ◽  
Test Results ◽  
Concrete Compressive Strength ◽  
Railway Bridges ◽  
Slab Track ◽  
Concrete Blocks ◽  
Sliding Slab

In recent years, several studies have investigated the sliding slab track for railway bridges. In the design of sliding slab tracks, one of the most important considerations is to evaluate the shear capacity of the lateral supporting concrete blocks in which dowel rebars are embedded. The predictions of the dowel behavior of rebars by existing models are considerably different. Therefore, in this study, the actual dowel behavior of the rebars embedded in a small concrete block was extensively investigated through experiments. Test variables were concrete compressive strength, dowel rebar diameter and yield strength, specimen thickness, and dowel rebar spacing. Existing model predictions were considerably different from test results. The maximum dowel force increased as concrete compressive strength and dowel rebar diameter increased, while it did not increase considerably with other test variables. Unlike in existing models, the shear slip at the maximum dowel force decreased as the dowel rebar diameter increased. Existing models significantly underestimated the maximum dowel force of the dowel rebars with small diameters and overestimated it for the dowel rebars with large diameters. This work can be useful for developing a more rational model to represent the actual dowel behavior of the rebars embedded in small concrete blocks.

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