Tests of Joints in AAC Masonry Walls

Figure 1.

Figure 2.

Figure 3.

Figure 4.

Figure 5.

Figure 6.

Figure 7.

Figure 8.

Figure 9.

Figure 10.

Calculated lengths of connectors

Type of connector	Displacements		Forces		Ultimate displacements
	Elastic phase	Failure phase	Elastic phase	Failure phase	Assumptions of the method	Condition of the connector’s rapture (21)
	uel mm	upl mm	Nel kN	Npl kN	uel,gr mm	ugr,y mm
B	2.48·10-4	3.72·10-4	10.4	15.6	1.69	0.68	0.02 mm(0.02t)	0.04 (0.04t)
F	1.64·10-1	2.78·10-1	15.1	25.6	1.76	0.79	1.19 mm(0.12ϕ)	3.14 (0.31ϕ)

Joint stiffness

Model	Elastic joint stiffness		Residual joint stiffness		Residual force
	Kt MN/m	Kt,mv MN/m	Kd MN/m	Kd,mv MN/m	Kr MN/m	Kr,mv MN/m
B_1	202	221	10	9	3	1
B_2	330		9		1
B_3	132		7		0
F_1	215	320	10	8	1	1
F_2	400		8		1
F_3	344		8		1

Testing program

Series name	Type of joint	l mm	A mm2	I mm4	fy N/mm2	Es N/mm2	No. of walls in series
P	Traditional masonry bond	--	--	--	--	--	3
B	Perforated wall junction strip b×t= 22×1 mm	300 (300 t)	22	1.83	144	66225	3
F	Steel bar ϕ10	300 (30 ϕ)	79	491	536	190500	3

Lengths of connectors determined based on the condition of forces acting in the joint

Type of connector	Elastic phase	Post-elastic phase	Failure phase	Mean value
	ecr,mv mm	ed,mv mm	eu,mv mm	e mm
B	0.35 (0.35t)	0.56 (0.56t)	0.87 (0.87t)	0.59 (0.59t)
F	23.8 (2.4ϕ)	48.6 (4.9ϕ)	53.0 (5.3ϕ)	41.8 (4.18ϕ)

Lengths of connectors determined from the conditions of displacements

Type of connector	Elastic phase	Failure phase	Limit length of the connector
	eel,u mm	epl,u mm	egr mm
B	11.2 (11t)	80.5 (80t)	300 t
F	30.7 (3.1 ϕ)	228.5 (22.9 ϕ)	30 ϕ

Test results

Model	Cracking force		Dowel force		Force at failure		Displacement at the moment of cracking		Dowel displacement		Displacement right before failure
	Ncr kN	Ncr,mv kN	Nd kN	Nd,mv kN	Nu kN	Nu,mv kN	ucr mm	ucr,mv mm	ud mm	ud,mv mm	uu mm	uu,mv mm
B_1	24	17.6	17	11.1	10	10.6	0.12	0.09(0.09t)	0.82	0.80	3.36	6.86(6.86t)
B_2	16		7		11		0.05		1.06		8.60
B_3	12		9		11		0.09		0.52		8.61
F_1	25	26.5	13	13.0	21	20.2	0.12	0.09(0.9ϕ)	1.29	1.75	6.96	8.31(0.83ϕ)
F_2	28		14		20		0.07		1.94		9.17
F_3	27		12		19		0.08		2.01		8.81

Comparison of test and calculation results

Joint model test			Calculation results
Cracking force	Failure force	Residual force	Cracking force (7)	Failure force (9)	Residual force (11)
Ncr,mv kN	Nu,mv kN	Nr,mv kN	Ncr kN	Nu kN	Nr kN
33.7	48.3	14.9	30.0	45.9	15.3
Cracking dis-placement	Failure dis-placement	Residual dis-placement	Cracking displacement (6)	Failure dis-placement (8)	Residual force (10)
ucr,mv mm	uu,mv mm	ur,mv mm	ucr mm	uu mm	ur mm
0.10	0.24	6.32	0.09	0.24	4.27