Study on Size Effect Law of Compressive Strength of Building Mortar under Uniaxial Compression

YANG Weijun, YUAN Shuai, YANG Chunxia

Abstract

In order to evaluate the size effect on the mechanical properties of mortar and to improve the size effect theory of mortar, size effect behaviours of mortar were investigated by using test method and theoretical analysis method. Based on the uniaxial compression test on 12 groups of mortar cube specimen and 12 groups of motar plate specimen, the size effect behaviour of mortar specimen and the relationship between mortar strength grade and size effect of compressive strength were investigated. The results indicate that the mortar compressive strength decreases with the increase of the specimen size, while the degree of size effect is enhanced with the increase of mortar strength grade. The energy release based size effect law was introduced to study the size effect of mortar geometrically similar specimen. The size effect of the mortar specimen of non-geometric similarity was also analyzed by correcting the Bazant size effect law with adding intensity term. Finally, the mortar size effect laws which can predict the size effect behavior of geometrically similar specimen, as well as the non-geometrically similar specimen，are derived，respectively. The predicted results of the proposed size effect law match well with test data. The research results provide an important basis for the establishment of the fine microscopic model of masonry, and also provide guidance for the engineering application of mortar.

 

Keywords: mortar plate specimen,  non-geometrically similarity, energy release, compressive strength, size effect



Full Text:

PDF


References


PLANAS J, GUINEA G V, ELICES M. Generalized size effect equation for quasi-brittle materials [J] . Materials and Structures, 1997, 20 (50): 671—687.

YANG L, SHEN X P. Damage theory and application of mass concrete structure [M].Shenyang: Liaoning Science and Technology Publishing House, 2016: 16.(In Chinese)

WEIBULL W. A Statistical theory of the strength of materials [J]. Proceedings of the American Mathematical Society, 1939, 151 (5) : 1034—1034.

BAZANT Z P, CHEN E P. Scaling of structures failure[J] . American Society of Mechanical Engineers, 1997, 50 (12): 593—672.

BAZANT Z P. Size effect in blunt fracture: concrete, rock, metal [J]. Journal of Engineering Mechanics, 1984, 110 (4): 518—535.

CARPINTERI A, FERRO G. Size effects on tensile fracture proper ties-a unified explanation based on disorder and fractality of concrete microstructure[J] . Materials and Structures, 1994, 27: 563—571

CARPINTERI A. Scaling laws and renormalization groups for strength and toughness of disordered materials [J] . International Journal of Solids and Structures,1994, 31 (3);291—302.

LI D. Research on size effect of concrete and RC columns [ D] . Beijing: College of Architecture and Civil Engineering, Beijing University of Technology, 2017: 138—140.(In Chinese)

SU J. The research the size effect of concrete behavior in compression and tension [D] . Changsha: College of Civil Engineering, Hunan University,2013: 79—84.(In Chinese)

ZHANG Y, LIU C Y, WANG Y Y, et al. Mesoscale modeling based numerical study on size effect of concrete compressive strength[J]. Journal of Building Structures, 2017, 38 (S1): 493—501.(In Chinese)

BAZANT Z P, PLANAS J. Fracture and size effect in concrete and other quasibrittle materials [M] . Boca Raton: CRC Press, 1998: 138—139.

GAJANAN M S, HARRY G H, RICHARD N W, et al. Structural modeling and experimental techniques [M]. Translated by ZHU S J, TONG Y S, et al. Beijing: China Railway Publishing House, 1989: 147—150.(In Chinese)


Refbacks

  • There are currently no refbacks.