1. Han A.L.- Gan. B. S. – Kristiawan S. A. – Trinh T. H. Han Aylie – Buntara S. Gan - S. A. Kristiawan – Trinh T. H. Diponegoro University, Semarang, Indonesia College of Engineering, Nihon University, Koriyama, Japan Civil Engineering Department, Sebelas Maret University THE BEHAVIOR OF FUNCTIONALLY GRADED CONCRETE AND THE PROSPECT OF MATERIAL OPTIMIZATION Central Europe towards Sustainable Building Prague 2016 (CESB16) June 22-24, 2016, Prague

2. Functionally Graded Concrete (FGC) was inspired by the study on the actual compression strength gradation of deep beams that exhibited a gradation in compression ultimate strength and stiffness throughout its depth (Hidayat et al., 2015) Background 2 Central Europe towards Sustainable Building Prague 2016 (CESB16) June 22-24, 2016, Prague Han A.L.- Gan. B. S. – Kristiawan S. A. – Trinh T. H.

3. Characteristics of FGC: the compressive strength is predominately influenced by the strength of the lower grade concrete, the stiffness of the material closely approaches the higher strength concrete. The resulting FGC does not follow the stress-strain responses as stated in the fib-CEB code (Buntara et al., 2015) 3 Central Europe towards Sustainable Building Prague 2016 (CESB16) June 22-24, 2016, Prague Han A.L.- Gan. B. S. – Kristiawan S. A. – Trinh T. H.

4. Potential benefits : An FGC element has the potentials of cement-use reduction, by optimizing the required strengths in accordance to the behavior of a section in bending. 4 Central Europe towards Sustainable Building Prague 2016 (CESB16) June 22-24, 2016, Prague A member in negative bending. The upper fibers do not require a high concrete compression strength and FGC can reduce cement use. P-57G-57/24 Han A.L.- Gan. B. S. – Kristiawan S. A. – Trinh T. H.

5. 5 Central Europe towards Sustainable Building Prague 2016 (CESB16) June 22-24, 2016, Prague Research Objective Experimental and Finite Element data: the material properties of a 400 mm section were as following: The resulting data were confirmed by the Finite Element Model using the layer- wise homogenization approach as developed by Pratama (2015) and Han et al. (2015). Material Compression strength f’ c (MPa) Initial Stiffness Modulus E (GPa) Poisson’s ratio ν P-5757.2334.690.23 G-57/2424.8828.920.25 Han A.L.- Gan. B. S. – Kristiawan S. A. – Trinh T. H.

6. 6 Central Europe towards Sustainable Building Prague 2016 (CESB16) June 22-24, 2016, Prague Response on a building proto-type: The FGC section is analyzed on a two- storey building frame Han A.L.- Gan. B. S. – Kristiawan S. A. – Trinh T. H.

7. Reinforcement Ratio ρ A section in bending is predominantly determined by the tensile steel. The presence of the FGC had little effect on the required steel ratio. The increase was 2.3% Serviceability The serviceability is influenced by the concrete stiffness and the cracked section’s moment of inertia. The P-57 and G-57/24 having an almost identical stiffness modulus resulted in a 15% of deflection increase 7 Central Europe towards Sustainable Building Prague 2016 (CESB16) June 22-24, 2016, Prague Results and Analysis Han A.L.- Gan. B. S. – Kristiawan S. A. – Trinh T. H.

8. Cement optimization 8 Central Europe towards Sustainable Building Prague 2016 (CESB16) June 22-24, 2016, Prague The G-57/24 section requires 161 kg/m 3 less cement compared to P-57. This reduction is a direct function of the relationship between the higher and lower strength concrete, and the depth of the beam section Han A.L.- Gan. B. S. – Kristiawan S. A. – Trinh T. H.

9. Assessing the advantages of FGC, two aspects are standing out; cement optimization and serviceability performance. A reduction in cement is cost effective, and impacts the environmental issue positively since less cement means a reduction in carbon emission during production. The stiffness modulus of FGC approaches the highest strength material, a FGC member will have the same deflection intensity as a homogeneous section. 9 Central Europe towards Sustainable Building Prague 2016 (CESB16) June 22-24, 2016, Prague Conclusion Han A.L.- Gan. B. S. – Kristiawan S. A. – Trinh T. H.

10. 10 Central Europe towards Sustainable Building Prague 2016 (CESB16) June 22-24, 2016, Prague Nihon University - Japan Diponegoro University - Indonesia