Title:
Reinforced Cementless Concrete: Mechanical Properties and Structural Performance
Author(s):
Maria Antonietta Aiello
Publication:
Web Session
Volume:
ws_S23_MariaAntoniettaAiello.pdf
Issue:
Appears on pages(s):
Keywords:
DOI:
Date:
4/2/2023
Abstract:
The ordinary Portland cement (OPC) concrete is nowadays the most consumed material, second only to water; on the other hand, the cement production is responsible for a significant percentage of the global carbon dioxide (CO2) emissions. In this scenario the use of cementless concrete becomes increasingly an effective alternative to reduce the environmental impact of concrete and reinforced concrete constructions. The high mechanical performances showed by geopolymer concrete led several researchers to investigate about possibilities of using this material in reinforced concrete structural elements. Since geopolymer binder has a different microstructure from ordinary Portland Cement (OPC) it is necessary to investigate its main mechanical proprieties, the stress transfer mechanisms between reinforcement and concrete and the behavior of structural elements. From the data available in literature, it seems that the mechanical properties of geopolymer concrete (GPC) are quite different from those of OPC concrete, thus more appropriate approaches should be defined for the qualification, design and control of that more sustainable material, based on further experimental and theoretical investigations. Generally, it has been observed that geopolymer concrete (GPC) has higher bond strength than OPC due to the higher compression strength and the dense and compact microstructure of GPC. This means that the existing design equation for bond strength prediction of ordinary concrete could be conservatively used also for GPC. In the present paper it is discussed a mechanical characterization of a GPC mix composed by only industrial by-products as ground granulated blast furnace slag (GGBFS) and silica fume. In particular, the compressive strength, elastic modulus and constitutive behavior were estimated. Moreover, the bond behavior of GPC with both steel and FRP (Fiber Reinforced Polymer) reinforcing bars is analyzed by means of direct pull-out tests.