Material characteristics

Database of material characteristics is based on production sheets of the individual manufacturers. Characteristics of general masonry units are calculated in accordance with EN 1996-1-1.

Characteristic compressive strength of masonry

Characteristic compressive strength of masonry is calculated using equation

where:	*f_k*	is the characteristic compressive strength of the masonry
	K	is a constant based on table 3.3
	*α,β*	are constants
	*f_b*	is the normalised mean compressive strength of the units
	*f_m*	is the compressive strength of the mortar

Modified equation for masonry made with general purpose mortar and lightweight mortar:

Modified equation for masonry made with thin layer mortar, in bed joints of thickness 0.5mm to 3mm, and clay units of Group 1 and 4, calcium silicate, aggregate units and aac units:

Modified equation for masonry units made with thin layer mortar, in bed joints of thickness 0.5mmto 3mm, and clay units of Group 2 and 3:

Value of the constant K is given in the table 3.3 in EN 1996-1-1. Where load acts parallel to the direction of the bed joints, the constant K should then be multiplied by 0.5 for units of Group 2 and 3. For masonry made with general purpose mortar where there is a mortar joint parallel to the face of the wall through the length of the wall, the constant K is reduced by 0.8.

The value K is multiplied by reduction factor dependent on the ratio g/t for shell bedded masonry.

where:	g	is the total width of the mortar strips
	t	is the wall thickness

Minimal value of this ratio is 0.4. The value of the reduction factor is shown in the graph below:

Characteristic shear strength of masonry

Characteristic shear strength of masonry f_vk for general purpose mortar, thin layer mortar in beds of thickness 0.5mm to 3.0mm or lightweight mortar with all joints filled is calculated using equation

but not greater than

where:	*f_vk*	is the characteristic shear strength of masonry
	*f_vko*	is the characteristic initial shear strength, under zero compressive stress
	*σ_d*	is the design compressive stress perpendicular to the shear in the member at the levelunder consideration, using the appropriate load combination based on the average verticalstress over the compressed part of the wall that is providing shear resistance
	*f_b*	is the normalised compressive strength of the masonry units

The characteristic shear strength of masonry using general purpose mortar or thin layer mortar in beds of thickness 0.5mm to 3.0mm or lightweight mortar having the perpend joints unfilled is calculated using equation

but not greater than

where:	*f_vk*	is the characteristic shear strength of masonry
	*f_vko*	is the characteristic initial shear strength, under zero compressive stress
	*σ_d*	is the design compressive stress perpendicular to the shear in the member at the levelunder consideration, using the appropriate load combination based on the average verticalstress over the compressed part of the wall that is providing shear resistance
	*f_b*	is the normalised compressive strength of the masonry units

The characteristic shear strength of shell bedded masonry is calculated using equation

but not greater than

where:	*f_vk*	is the characteristic shear strength of masonry
	*f_vko*	is the characteristic initial shear strength, under zero compressive stress
	g	is the total width of the mortar strips
	t	is the wall thickness
	*σ_d*	is the design compressive stress perpendicular to the shear in the member at the levelunder consideration, using the appropriate load combination based on the average verticalstress over the compressed part of the wall that is providing shear resistance
	*f_b*	is the normalised compressive strength of the masonry units

Characteristic flexural strength of masonry

Characteristic flexural strength of masonry is determined according to the chapter 3.6.3.

Modulus of elasticity

Modulus of elasticity is calculated using equation

where:	*f_k*	is the characteristic compressive strength of masonry
	*K_E*	is a constant; value is 1000

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