In situ mechanical investigation of rammed earth: Calibration of minor destructive testing

Lombillo, I.; Villegas, L.; Fodde, Enrico; Thomas, Carlos

doi:10.1016/j.conbuildmat.2013.10.090

“…However, using nondestructive techniques to determine the in-situ characteristics of RE walls is less reported, although several studies can be cited. Lombillo et al [26] used minordestructive techniques such as flat jack, hole-drilling, and mini-pressure meter. Bui et al [27] developed an analytical procedure to determine the Young's modulus of RE walls from the non-destructive vibrational measurements.…”

Section: Introductionmentioning

confidence: 99%

Assessing the Rebound Hammer Test for Rammed Earth Material

Bui

¹

2017

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Rammed-earth (RE) is a construction material manufactured from the soil. The soil is compacted at its optimum water content, inside a formwork to build a monolithic wall. RE material is attracting renewed interest throughout the world thanks to its sustainable characteristics: low embodied energy, substantial thermal inertia, and natural regulator of moisture; on the other hand, the existing historic RE buildings is still numerous. This is why several research studies have been carried out recently to study different aspects of this material. However, few investigations have been carried out to explore the possibility of applying the nondestructive techniques on RE walls. This paper presents an assessment of the well-known rebound hammer test on RE walls. The calibration curves of the rebound hammer test have been established for conventional concrete where the rebound number is more than 20. For RE material with lower compressive strengths, a new calibration curve must be established. In the present study, two soils were used and different homogenized specimens with different dry densities were manufactured and tested, to plot a general calibration curve. Then, this calibration curve was applied to RE specimens; different results at different positions in an earthen layer were observed, due to the inhomogeneity of the material. The final results showed an acceptable accuracy of the calibration curve in the prediction of the compressive strength of RE material.

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“…Due to this fact, in this case, the compressive strength was estimated following the suggestion of Lombillo et al 19,25 by fitting a logarithmic curve on the non-linear region of the envelope loading cycles (stress-strain relationship) and considering the maximum stress associated with a deformation of 3‰ as proposed in. 19,25 Test on rubble stone masonry walls A total of four tests were performed on walls made with rubble limestone with air lime mortar: one test on the back façade wall of the ''Pombalino'' building (P.1) and three tests on the side external wall of the ''Gaioleiro'' building (G.1, G.2, and G.3). The test setup (test P.1 as an example) and the relationship between the average stress in the masonry (σ m ) and the average vertical strain (ε V ) for both cycles of pressure are displayed in Fig.…”

Section: Double Flat-jack Testsmentioning

confidence: 99%

Mechanical Characterization of Masonry Walls With Flat-Jack Tests

Simões

¹

,

Bento

²

,

Gago

³

et al. 2015

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The results from an experimental campaign on old masonry buildings from Lisbon are presented and discussed. The tests aim at the evaluation of the masonry deformability properties in compression and the shear strength parameters based on flat-jack testing technique. Tests were carried out in both internal brick masonry walls and external rubble limestone masonry walls. The evaluation of the shear parameters was done according to a new testing technique-shear tests on masonry walls with flat-jacks-involving more than one masonry unit. One of the goals is the calibration and development of this testing technique and to show its first application to the test of rubble stone masonry walls. For that, the experimental technique is fully explained in this paper, and the results of some in situ tests are used to discuss the calibration procedure. Because of the characteristics of the walls, in particular, the great heterogeneity and thickness of the external masonry walls, the application of the flat-jack testing technique involved some uncertainties that are described and debated in this work.

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“…Thus, the Young's modulus was defined as the secant value to 1/3 of the masonry compressive strength E s(1/3 f c ) according to EN 1052-1. 19,25 Test on rubble stone masonry walls A total of four tests were performed on walls made with rubble limestone with air lime mortar: one test on the back façade wall of the ''Pombalino'' building (P.1) and three tests on the side external wall of the ''Gaioleiro'' building (G.1, G.2, and G.3). In fact, the load applied by the top flat-jack needs to be reacted and cannot be larger than the dead load on the wall.…”

Section: Double Flat-jack Testsmentioning

confidence: 99%

Mechanical Characterization of Masonry Walls With Flat-Jack Tests

Simões

¹

,

Bento

²

,

Gago

³

et al. 2016

View full text Add to dashboard Cite

The results from an experimental campaign on old masonry buildings from Lisbon are presented and discussed. The tests aim at the evaluation of the masonry deformability properties in compression and the shear strength parameters based on flat-jack testing technique. Tests were carried out in both internal brick masonry walls and external rubble limestone masonry walls. The evaluation of the shear parameters was done according to a new testing technique-shear tests on masonry walls with flat-jacks-involving more than one masonry unit. One of the goals is the calibration and development of this testing technique and to show its first application to the test of rubble stone masonry walls. For that, the experimental technique is fully explained in this paper, and the results of some in situ tests are used to discuss the calibration procedure. Because of the characteristics of the walls, in particular, the great heterogeneity and thickness of the external masonry walls, the application of the flat-jack testing technique involved some uncertainties that are described and debated in this work.

show abstract

In situ mechanical investigation of rammed earth: Calibration of minor destructive testing

Cited by 39 publications

References 18 publications

Assessing the Rebound Hammer Test for Rammed Earth Material

Assessing the Rebound Hammer Test for Rammed Earth Material

Mechanical Characterization of Masonry Walls With Flat-Jack Tests

Mechanical Characterization of Masonry Walls With Flat-Jack Tests

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