3D BEHAVIOR OF SHOTCRETED LIGHT WEIGHT PANEL BUILDINGS Waiel MOURTAJA 1 , Faruk KARADOGAN 2 , Ercan YUKSEL 3 And Alper ILKI 4 Summary 2 Specially fabricated two layers of reinforcement grids which are in contact by zig zag shape continuous cross bars, are used to construct first the skeletal part of a 3D structure. Since a layer of foam sheet has been placed in between the two surfaces of reinforcement cages there is practically no difficulty for shotcrete application from each side during the construction phase. 1/2 scale model of one story specimen has been prepared in the laboratory using this material and construction technique and tested for lateral loads. The light weight panels cut the total weight of the structure roughly in half. And the monotonic lateral loading indicates that ultimate load reached may be 10 times higher than the design load and all relative displacement requirements are perfectly satisfied. The 2D test results of panels made of similar material have been summarised first and then used in theoretical work presented here in. Introduction Specially prepared two layer wire cage with a foam layer in between have been used to strengthen the damaged RC frames, see Fig 1a, or used to build low rise structures, see photographs 1-5. The lateral and vertical cross sections of the special material used is given in Figure 2b. After having installed, the two surfaces of diaphragms are shotcreted, (see Photograph 5). Several techniques, to connect the damaged frame to the diaphragm have been employed and tested. The envelopes of the hysteresis curves achieved at the end of these two cyclic loading are presented all together in Fig 1b. The details of this investigation can be found elsewhere [2]. Curve E in Fig 1b belongs to the reinforced concrete frame subjected to the same displacement pattern prior to the installation of diaphragms. Curve B which has been obtained analytically subtracting the curve E from curve A which corresponds to the panels with the same detailing features of the panels used in construction of 3D specimen investigated in this paper. Curve B is given independently in Fig 1c from which the relationship between shear stresses and shear distortions is approximately derived and presented separately in Fig 1d. The way followed up in this derivation has been summarised in the same figure by means of two equations. Declined part of that curve has not been referred later on in the theoretical calculation, but the lateral line has been utilised instead. The efficiency of added diaphragms on the lateral stiffness and strength of the damaged frame can easily be observed by the comparison of the slopes at the beginning and the ultimate points they reached. In Fig 1a one can hardly see the fine cracks at ultimate load level on the surface and the limited amount of damage at the diaphragm corners.