A Comparative Study on the Seismic Behavior of RCC Framed Building and Composite Framed Building

Since different types of RCC and steel Concrete Composite structures with various floor systems are used for multistory buildings, there is a great prospective for increasing the volume of steel in construction industry, especially in Nepal. As the population in cities is increasing rapidly and the land is limited, there is a need of vertical growth of buildings in cities. So, for the fulfilment of this purpose a large number of mediums to high rise buildings are being constructed on a large scale

For medium to high rise buildings, the conventional RCC structures is not excellent choice as there is in-creased dead load along with the span restrictions and consuming more time to construct. This study gives a brief description of various components of steel-concrete composite structure. A comparative analysis of composite and RCC framed structure was carried out by using ETABS software. The total cost comparison of composite framed structure is more economical in case of high-rise buildings than RCC framed structure and the construction time of Composite framed structure requires much less duration than RCC structure [1]. In composite framed structure the dead weight, lateral Displacement, twisting moment and shear force are observed to be decreased whereas the stiffness is found to be increased than RCC framed structure [2]. Literature review study summarizes that the composite sections using steel encased and concrete in filled are economical option if de-sign well and time effective solution in major civil structures such as bridges, warehouses and high-rise buildings.

LITERATURE REVIEW:

(Aniket & Yogesh, 2013): The work on this paper is focused on RCC and Composite framed buildings of (G+9), (G+12), (G+15) and (G+18) storey using ES analysis method in STAAD-Pro 2007 software pro-gram. On this research paper, it is concluded that although the overall cost of Composite framed structure is found to be more than RCC framed system, the reduction in percentage of the direct cost due to the rapid erection of the components in Composite framed structure will lead to the fast finishing touch of the structure. Moreover, the reduction in the dimension of structural members makes it more stable towards lateral loads.  (Wagh & Waghe, 2014): In this research paper a comparative study of RCC and Composite framed structure of four specific multistoried buildings i.e. (G+12, G+16, G+20 and G+24) are taken into consideration using Equivalent Static Analysis method in STAAD pro software. After analyzing, it's observed that in a Composite structural system, the values of beam end forces and the moments are found to be much less as compared to RCC structural system and the overall cost is found to be (10-14) % much less than RCC framed structure which concludes that composite structural system is found to be more cost effective in case of high-rise buildings than RCC system. (Mahesh Suresh Kumawat and L G kalurkar, 2014): On this studies paper, RCC and Composite framed structure are considered for comparative study of (G+9) storey commercial building using ES Analysis method in SAP 2000 software program. After analysis, it is observed that the dead weight of Composite framed system is found to be (15-20) % much less than RCC framed structure resulting the seismic forces to be reduced by (15-20) % than RCC framed structure. The axial forces in Composite systems are found to be (20-30) % much less than RCC framed systems.

(Nitish et al., 2015): This research work concentrates on the study of Composite framed and RCC framed structure of (B + G + 11) storey building located in EQ region III having wind velocity of 39 m/s as per IS 875 part III. Equivalent Static method is used and modelled in ETABS software program. The outcomes thus received are compared for various parameters. After analysis, it is observed that the reduction within the self-weight of the Composite framed structure is decreased by 9.40 % as com-pared to RCC framed structure. The axial forces in column of Composite framed structure are observed to be decreased by 9.0% than RCC framed structure.

(Zaveri et al., 2016): This research paper studies a comparison among steel, RCC and composite framed structure considering various parameters like seismic performance, deformations, forces, moments, cost and weight of building structure. On this research paper, it is concluded that the overall response of composite structure is found to be better than RCC structure. The composite framed system produces less displacement and resists more lateral forces than RCC structure.

(Damam 2016): This research paper focus on comparative study of RCC and steel-Concrete Composite framed structure of (G+15) storey commercial building using ES analysis method in STAAD pro soft-ware program. The building is located in earth-quake zone IV having wind speed 50m/s as per IS 875 part III. After analysis it is observed that the deflection & storey drift of composite structure is observed to be almost double than that of RCC structure however the deflection is within the permissible restriction.

STATEMENTS OF PROBLEM:

Several research studies have concluded that for high rise buildings, steel concrete composite structures are observed to be the best choice among RCC and steel structure either economically or lateral load resistant capability. Unfortunately, in all the studies we get that the researches have been done in the same type of building models i.e. simple and symmetrical using the same type of analysis techniques i.e. either by ESA or RSA method. So the research is not enough to come to the conclusion that composite structures are better than RCC structure. This means there is need to explore it further. Hence this research study tries to identify a comparative analysis on the performance and seismic behavior of RCC and composite building structures using both RSA and PA method of analysis considering various parameters to find out better alternative solution between RCC and Composite structural system.

OBJECTIVES OF STUDY:

The aim of this research is to study a comparison on the Seismic Behavior of RCC Framed Building and Composite Framed Building.

Dimensions and Models:

In this research, two buildings are modelled in ETABS. These models are of (G+33) storey with RCC and composite framed buildings with the identical floor plan, floor height, slab thickness, floor finishers, wall load, wind load, live load and seismic load all are being the same throughout the analysis. The analysis is carried out using Response Spectrum and Pushover Analysis Method. In the present work (G+33) storey with RCC and composite framed buildings are considered for the study. For the both type of buildings, the following data is used including the loadings as per relevant IS code.

Table 1. Collection of Data for Analysis of (G+33)