Self Compacted Concrete
Shamsad Ahmad, Abul Kalam Azad, and Mohammed Abdul Hameed
A STUDY OF SELF-COMPACTING CONCRETE MADE WITH MARGINAL AGGREGATES
Shamsad Ahmad∗, Abul Kalam Azad, and Mohammed Abdul Hameed
Department of Civil Engineering King Fahd University of Petroleum & Minerals Dhahran, Saudi Arabia
1. INTRODUCTION Self-compacting concrete (SCC), developed first in Japan in the late 1980s, represents one of the most significant advances in concrete technology in the last two decades. SCC was developed to ensure adequate compaction through self-consolidation and facilitate placement of concrete in structures with congested reinforcement and in restricted areas. SCC can be described as a high performance material which flows under its own weight without requiring vibrators to achieve consolidation by complete filling of the formworks even when access is hindered by narrow gaps between reinforcement bars [1]. The high flowability of SCC makes it possible to fill the formwork without vibration [2]. The constituent materials used for the production of SCC are the same as those for conventionally vibrated normal concrete except that SCC contains a lesser amount of aggregates and larger amount of powder (cement and filler particles smaller than 0.125 mm) and special plasticizer to enhance flowability. Fly ash, glass filler, limestone powder, silica fume, etc. are used as the filler materials. High flowability and high segregation resistance of SCC are obtained by using: (i) a larger quantity of fine particles, i.e. a limited aggregate content (coarse aggregate: 50% of the concrete volume and sand: 40% of the mortar volume) [3]; (ii) a low water/powder ratio; and (iii) a higher dosage of superplasticizer and stabilizer [4, 5]. Stabilizer is needed for SCC mixes for maintaining proper cohesiveness so that highly flowable SCC would not segregate. Typical ranges of proportions and quantities of the constituent materials for producing SCC are reported in the literature [2, 6–9]. Relevant
A STUDY OF SELF-COMPACTING CONCRETE MADE WITH MARGINAL AGGREGATES
Shamsad Ahmad∗, Abul Kalam Azad, and Mohammed Abdul Hameed
Department of Civil Engineering King Fahd University of Petroleum & Minerals Dhahran, Saudi Arabia
1. INTRODUCTION Self-compacting concrete (SCC), developed first in Japan in the late 1980s, represents one of the most significant advances in concrete technology in the last two decades. SCC was developed to ensure adequate compaction through self-consolidation and facilitate placement of concrete in structures with congested reinforcement and in restricted areas. SCC can be described as a high performance material which flows under its own weight without requiring vibrators to achieve consolidation by complete filling of the formworks even when access is hindered by narrow gaps between reinforcement bars [1]. The high flowability of SCC makes it possible to fill the formwork without vibration [2]. The constituent materials used for the production of SCC are the same as those for conventionally vibrated normal concrete except that SCC contains a lesser amount of aggregates and larger amount of powder (cement and filler particles smaller than 0.125 mm) and special plasticizer to enhance flowability. Fly ash, glass filler, limestone powder, silica fume, etc. are used as the filler materials. High flowability and high segregation resistance of SCC are obtained by using: (i) a larger quantity of fine particles, i.e. a limited aggregate content (coarse aggregate: 50% of the concrete volume and sand: 40% of the mortar volume) [3]; (ii) a low water/powder ratio; and (iii) a higher dosage of superplasticizer and stabilizer [4, 5]. Stabilizer is needed for SCC mixes for maintaining proper cohesiveness so that highly flowable SCC would not segregate. Typical ranges of proportions and quantities of the constituent materials for producing SCC are reported in the literature [2, 6–9]. Relevant