Formwork Pressure of Self-Consolidating Concrete Containing Recycled Coarse Aggregates

Joseph J. Assaad; Jacques Harb

doi:10.14359/51689494

Influence of coarse aggregate on shear resistance of self-consolidating concrete beams

Revista IBRACON de Estruturas e Materiais ◽

10.1590/s1983-41952017000100003 ◽

2017 ◽

Vol 10 (1) ◽

pp. 30-40

Author(s):

G. SAVARIS ◽

R. C. A. PINTO

Keyword(s):

Shear Strength ◽

Failure Modes ◽

Coarse Aggregate ◽

Concrete Beams ◽

Shear Resistance ◽

Self Consolidating Concrete ◽

Coarse Aggregates ◽

Lower Shear ◽

Nominal Size ◽

High Flowability

Abstract Self-consolidating concrete is characterized by its high flowability, which can be achieved with the addition of superplasticizer and the reduction of the amount and size of coarse aggregates in the concrete mix. This high flowability allows the concrete to properly fill the formwork without any mechanical vibration. The reduction in volume and particle size of the coarse aggregates may result in lower shear strength of beams due to a reduced aggregate interlock. Therefore, an experimental investigation was conducted to evaluate the influence of the reduction in the volume fraction and the nominal size of coarse aggregate on concrete shear strength of self-consolidating beams. Six concrete mixes were produced, four self-consolidating and two conventionally vibrated. A total of 18 beams, with flexural reinforcement but without shear reinforcement were cast. These beams were tested under a four-point loading condition. Their failure modes, cracking patterns and shear resistances were evaluated. The obtained shear resistances were compared to the theoretical values given by the ACI-318 and EC-2 codes. The results demonstrated a lower shear resistance of self-consolidating concrete beams, caused mainly due to the reduced aggregate size.

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Formwork Pressure of Self-Consolidating Concrete in Tall Wall Field Applications

Transportation Research Record Journal of the Transportation Research Board ◽

10.1177/0361198105191400101 ◽

2005 ◽

Vol 1914 (1) ◽

pp. 1-7 ◽

Cited By ~ 1

Author(s):

Fernando Tejeda-Dominguez ◽

David A. Lange ◽

Matthew D. D'Ambrosia

Keyword(s):

Hydrostatic Pressure ◽

Use Of Self ◽

Conventional Concrete ◽

Concrete Material ◽

Self Consolidating Concrete ◽

Structural Applications ◽

Formwork Pressure ◽

High Column

The growing interest in the use of self-consolidating concrete (SCC) for a wide variety of structural applications has initiated a reexamination of its properties and current construction practices and how they compare with those of conventional concrete. One property of interest is the formwork pressure of SCC and how it relates to that of conventional concrete. This work presents the results for three tall walls (28, 21.7, and 13 ft tall) cast slowly with SCC and a 10.6-ft-high column poured quickly by using the same concrete used in one of the walls. The research demonstrates that the pressure of SCC against the formwork drops quickly just after the concrete material is placed. Measurements from the walls poured slowly show that the maximum recorded pressure falls far below the hydrostatic pressure and is closely related to the pouring rate. The experiments also reveal that the formwork pressure exerted by SCC can be revitalized if the SCC is vibrated, even if stiffening is already in progress.

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