Predict the Ultimate Moment Capacity of Reactive Powder Concrete Beams Exposed to Fire Flame Using Artificial Neural Network and Multiple Linear Regression Models

Abstract

I. INTRODUCTIONReactive powder concrete (RPC) is the generic name for a class of cementitious composite materials developed by the technical division of Bouygues, laboratory in France in the early 1990's. It is characterized by extremely good physical properties, particularly strength and ductility [1]. RPC is a relatively new cement-based material composed of cement, ultra-fine reactive powder, and high-quality fine aggregate. Through elimination of the coarse aggregates and reducing the water-tocementitious material ratio, RPC has the unique properties of ultra-high compressive strength and excellent durability [2]. RPC is a new generation concrete developed through microstructure enhancement techniques for cementitious materials. As compared to ordinary cementbased materials, the primary improvements of RPC include the particle size homogeneity, porosity, and microstructures [3]. Nowadays, RPC is regarded as a promising material for special pre-stressed and precast concrete members, including those industrial and nuclear waste storage facilities.More and more attention has been paid on the mechanical properties of RPC at room temperature [3], [4], but few studies have been conducted on the residual mechanical properties of RPC after elevated temperatures [5], [6].Most of the previous studies indicated two important components (as key components) for the successful performance of the concrete in fire; the first deals with its essential properties as a construction material, and the second one deals with its functionality in a structure. Concrete was known to be non-combustible with slow rate of heat transfer [7].Many researchers studied the effect of fire on ordinary concrete, reinforced concrete members on exposing such members to high temperatures in special ovens or fire flame. They worked on the strength and deformation properties at elevated temperatures. However, no works were done on the structural behavior of reactive powder concrete (RPC) beam specimens exposed to direct fire flame.

Experimental investigation on the post-fire performance of reactive powder concrete columns

“…The internal cracks are the main cause of spalling. There is, however, some doubt surrounding whether the surface layer is split partially or completely at various depths at the core of the column, taking into account that there is no considerable damage on the surface (Kadhum & Mohammed, 2017). The vertical displacement of the reinforced RPC and NSC columns, as shown in Figure 4, has a similar trend tion (expansion) of the RPC and NSC column specimens was mostly because of the thermal concrete expansion and steel, though in the intermediate stages both load and thermal expansion had a substantial influence.…”