Production of high performance, fibre reinforced, self-compacting concrete

Abstract

Reinforcement of materials with fibre was used in various regions in antiquity up to modern times to enhance the characteristics of brittle materials. For instance, in the Egyptian period, straw was used to reinforce bricks which would be produced out of mud and then sun dried. The use of steel fibres in concrete and other types of fibres has gained popularity in the past decades to improve ductility and toughness of concrete bul also Lo improve ils properties with regards Lo early stage cracking behaviour. During the last decodes of the 20th century, self compacting concrete was developed leading to an improved concrete performance and higher durability since the materials relies less on the workforce in particular with regards compaction, the latter being a fundamental property of concrete. This material results in improved performance since it does not require external or internal compaction. This type of concrete includes additions leading to particular rheological characteristics. The additions and constituents together with the properties of the fresh and hardened concrete also lead to an improved durability. This study adressed the production of a self-compared fibre reinforced concrete with self-healing properties through the inclusion of crystalline admixtures. Fibres may be included in concrete resulting in a random orientation in the concrete matrix. However, self-compacting concrete has the nbility to flow without vibration or external action. This characteristic was exploited in order to lead to a prevailing orientation of fibres. This desirable characteristic enhance better stress distribution within structural elements. The presence of additions in self-compacting concrete was required to address the rheological characteristics. These additions also lead to improved durability performance including autogenous healing. The addition of crystalline admixtures also leads to improved durability performance in view of the self-healing capability of the material. Whilst the fibres used to control crack width and crack formation lead to an improved ductility and toughness, the crystalline admixtures improve the durability properties through the self-healing capabilities of the material.