Importance of Sand Grading on the Compressive Strength and Stiffness of Lime Mortar in Small Scale Model Studies
Affiliation(s)
1 Department of Civil Engineering, Abubakar Tafawa Balewa University, Bauchi, Nigeria. 2 Cardiff University, Cardiff, UK.
1 Department of Civil Engineering, Abubakar Tafawa Balewa University, Bauchi, Nigeria. 2 Cardiff University, Cardiff, UK.
ABSTRACT
Mortars provide the continuity required for the stability and exclusion of weather elements in masonry assemblies. But because of the heterogeneity of the mortar, its mechanism of behaviour under different load effects is dependent on the properties of the constituents of the mortar. The aim of paper is to determine the effect sand grading for various cement-sand-lime mortar designations (BS) and strength classes (EC) on the compressive strength and stiffness of mortar. Two silica sands; HST 95 and HST60 were used to make mortars in three strength classes: M2, M4 and M6, corresponding to mortar designations iv, iii and ii respectively. The results show that mortar made with the HST60 sand (coarser grading) usually resulted in mortar with a higher compressive strength and stiffness. The One Way ANOVA analysis of both compressive strength and stiffness at a significance level of 5% on the effect of sand grading on the two parameters also shows that they are both significant. There is also strong evidence of a linear correlation between the stiffness and compressive strength. The results indicate that in order to replicate full scale behaviour of masonry at model scales, the grading of fine aggregate in the models should be similar so as to properly model full scale behavior.
Mortars provide the continuity required for the stability and exclusion of weather elements in masonry assemblies. But because of the heterogeneity of the mortar, its mechanism of behaviour under different load effects is dependent on the properties of the constituents of the mortar. The aim of paper is to determine the effect sand grading for various cement-sand-lime mortar designations (BS) and strength classes (EC) on the compressive strength and stiffness of mortar. Two silica sands; HST 95 and HST60 were used to make mortars in three strength classes: M2, M4 and M6, corresponding to mortar designations iv, iii and ii respectively. The results show that mortar made with the HST60 sand (coarser grading) usually resulted in mortar with a higher compressive strength and stiffness. The One Way ANOVA analysis of both compressive strength and stiffness at a significance level of 5% on the effect of sand grading on the two parameters also shows that they are both significant. There is also strong evidence of a linear correlation between the stiffness and compressive strength. The results indicate that in order to replicate full scale behaviour of masonry at model scales, the grading of fine aggregate in the models should be similar so as to properly model full scale behavior.
Cite this paper
Mohammed, A. , Hughes, T. and Abubakar, A. (2015) Importance of Sand Grading on the Compressive Strength and Stiffness of Lime Mortar in Small Scale Model Studies. Open Journal of Civil Engineering, 5, 372-378. doi: 10.4236/ojce.2015.54037.
Mohammed, A. , Hughes, T. and Abubakar, A. (2015) Importance of Sand Grading on the Compressive Strength and Stiffness of Lime Mortar in Small Scale Model Studies. Open Journal of Civil Engineering, 5, 372-378. doi: 10.4236/ojce.2015.54037.
References
[1] Lenczner, D. (1972) Elements of Loadbearing Brickwork. Pergamon Press, Oxford. [2] Mohammed, A. (2006) Experimental Comparison of Brickwork Behaviour at Prototype and Model Scales. Cardiff University, Cardiff. [3] Hendry, A.W., Sinha, B.P. and Davies, S.R. (1997) Design of Masonry Structures. 3rd Edition, E & FN Spon, London.
http://dx.doi.org/10.4324/9780203362402 [4] Anderson, C. and Held, L.C. (1986) The Effect of Sand Grading on Mortar Properties and the Tensile Bond of Brickwork Specimens. Proceedings of the British Masonry Society, No. 1, Stoke on Trent. [5] British Standards Institution (2002) Aggregates for Mortar. (BSI), B.S.I., BS EN 13139:2002. British Standards Institution, London. [6] British Standards Institution (2000) Cement. Composition, Specifications and Conformity Criteria for Common Cements. (BSI), B.S.I., BS EN 197-1:2000. British Standards Institution, London. [7] British Standards Institution (2001) Building Lime. Definitions, Specifications and Conformity Criteria. (BSI), B.S.I., BS EN 459-1:2001. British Standards Institution, London. [8] British Standards Institution (1998) Methods of Testing Mortars, Screeds and Plasters. (BSI), B.S.I., BS 4551: Part 1:1998. British Standards Institution, London. [9] British Standards Institution (1999) Methods of Tests for Mortar for Masonry—Part 11: Determination of Flexural and Compressive Strength of Hardened Mortar. (BSI), B.S.I., BS EN 1015-11:1999. British Standards Institution, London. [10] British Standards Institution (1995) Code of Practice for Use of Masonry: Part 2: Structural Use of Unreinforced Masonry. (BSI), B.S.I., BS 5628. British Standards Institution, London. [11] Hendry, A.W. (1998) Structural Masonry. 2nd Edition, Macmillan Press, London.
http://dx.doi.org/10.1007/978-1-349-14827-1
[1] Lenczner, D. (1972) Elements of Loadbearing Brickwork. Pergamon Press, Oxford. [2] Mohammed, A. (2006) Experimental Comparison of Brickwork Behaviour at Prototype and Model Scales. Cardiff University, Cardiff. [3] Hendry, A.W., Sinha, B.P. and Davies, S.R. (1997) Design of Masonry Structures. 3rd Edition, E & FN Spon, London.
http://dx.doi.org/10.4324/9780203362402 [4] Anderson, C. and Held, L.C. (1986) The Effect of Sand Grading on Mortar Properties and the Tensile Bond of Brickwork Specimens. Proceedings of the British Masonry Society, No. 1, Stoke on Trent. [5] British Standards Institution (2002) Aggregates for Mortar. (BSI), B.S.I., BS EN 13139:2002. British Standards Institution, London. [6] British Standards Institution (2000) Cement. Composition, Specifications and Conformity Criteria for Common Cements. (BSI), B.S.I., BS EN 197-1:2000. British Standards Institution, London. [7] British Standards Institution (2001) Building Lime. Definitions, Specifications and Conformity Criteria. (BSI), B.S.I., BS EN 459-1:2001. British Standards Institution, London. [8] British Standards Institution (1998) Methods of Testing Mortars, Screeds and Plasters. (BSI), B.S.I., BS 4551: Part 1:1998. British Standards Institution, London. [9] British Standards Institution (1999) Methods of Tests for Mortar for Masonry—Part 11: Determination of Flexural and Compressive Strength of Hardened Mortar. (BSI), B.S.I., BS EN 1015-11:1999. British Standards Institution, London. [10] British Standards Institution (1995) Code of Practice for Use of Masonry: Part 2: Structural Use of Unreinforced Masonry. (BSI), B.S.I., BS 5628. British Standards Institution, London. [11] Hendry, A.W. (1998) Structural Masonry. 2nd Edition, Macmillan Press, London.
http://dx.doi.org/10.1007/978-1-349-14827-1