Know-How

Casting a large GFRC Sink - GFRC, Glass Fiber Reinforced Concrete

I did not edit out a lot of footage so people could get a feel for what it takes to cast a project such as this in real time. Thanks to Eric Schaeffer and Dan from Majestic Concrete Design for demonstrating their technics. Materials Used: • Trinic TEC-10 Admix (approved for use in PCI certified plants) • Trinic Plasticizer • 3 mm HD fiber, available from Trinic • ½” Cemfill 60 Bundled Glass Fiber, available from Trinic • Trinic White Silica Fume • Portland Cement • Sand

www.trinic.us – info@trinic.us – 800-475-1975

Reference : Flavia Ribeiro Furtado de Mendonca / University of Nebraska-Lincoln

Ultra-high performance concrete (UHPC) is a new class of concrete that has superior workability, as well as mechanical and durability properties that far exceed those of conventional concrete. To achieve these properties, a very dense internal structure and the very low water-to-binder ratio (w/b) generally are necessary. While particle packing models are typically used to design UHPC, due to the complexity of the composition interaction and characteristics of UHPC, these models might not necessarily provide the best design, which leads to the need of experimental study to justify UHPC performance. The evaluation of the impact of various design parameters on the properties of UHPC is also needed. A study and evaluation were performed with multiple series of UHPC mixtures prepared with different design parameters and considerations. The impacts of different aggregate, types of fibers, High Range Water Reducing (HRWR), w/b, types of cement, types and quantities of supplemental cementitious materials (SCMs), and different total binder content on UHPC performance were presented. Furthermore, the extensive amount of fine materials, the absence of coarse aggregate, and the very low w/b often make the process of UHPC production challenging. This study included evaluations of the impacts of mixers on the properties of fresh and hardened UHPC. The comparison of these mixers was used to determine whether mixtures developed in the laboratory were comparable to those used in the field.

Reference : 

Soca Anggoro Wulan Highway and Water Resource Office, Tangerang, INDONESIA

Iman Satyarno Department of Civil and Environment Engineering, Universitas Gadjah Mada, Yogyakarta, INDONESIA

Ashar Saputra Department of Civil and Environment Engineering, Universitas Gadjah Mada, Yogyakarta, INDONESIA

Mix design for Self Compacting Concrete or SCC cannot be conducted directly because there are many control parameters in its rheological properties. This case becomes more complex if it should achieve a high compressive strength. The following is the simple approach that can be used, firstly, determining the flow of mortar mix which was designed based on the high strength determination. The mix design of SCC is then determined by adding the coarse aggregate in the mortar mix. In this research, the design of mix mortar flow with ultra-high compressive strength was made by the type I cement, i.e. 15% of cement weight silica fume with the ratio of the cement and the fine aggregate was 1 : 0.35, the fine aggregates was on the VI graded and the superplasticizer content was 1.3%, 1.4%, 1.5% and 1.6%. In case of the SCC, the coefficient was taken on 1.4, 1.6, and 1.8 from the volume of void aggregate, the coarse aggregate value was using the remaining volume of absolute mortar on one cubic meter concrete with the size of 4.8 mm - 9.6 mm. Test results showed that the mortar flowability was 170 mm, 180 mm, 220 mm and 250 mm with the compressive strength was 83.1 MPa, 96.8 MPa, 111.4 MPa, and 135.5 MPa respectively. Mortar mix with 1.6% superplasticizer was then used for making the SCC and the results showed that the concrete flow was 460 mm, 580 mm and 660 mm while the compressive strength was 88.2 MPa, 100.0 MPa, and 97.9 MPa. Therefore, it can be concluded that by using this approach, SCC can have 580 mm of flow and 100 MPa for compressive strength.

INTRODUCTION

Concrete has come a long way since its use in building the Roman Coliseum in 70 A.D. New methods of construction as well as improvement in cement formulas, aggregates and admixtures have significantly increased the type of projects for which concrete can be used. The strength and properties of various concrete mixes have led the way for larger buildings, safe and sound bridges and more durable structures. With the invention of reactive powder concrete (RPC), the use of concrete has increased. RPC with trade name „DUCTAL‟ was developed in France by researchers Mr.Richard and Mr. Cheyrezy in the early 1990s at Bouygues, laboratory in France. The world‟s first RPC structure, the Sherbrooke Bridge in Canada, was constructed in July 1997. RPC is an ultra-high-strength and high ductility cementitious composite with advanced mechanical and physical properties. It is a special concrete where the microstructure is optimized by precise gradation of all particles in the mix to yield maximum density. It extensively uses the pozzolanic properties of highly refined silica fume and optimization of the Portland cement chemistry to produce the highest strength hydrates. RPC was nominated for the 1999 nova awards from the construction innovation forum. RPC has been used successfully, for isolation and containment of nuclear wastes in Europe due to its excellent impermeability. This new material demonstrates greatly improved strength and durability characteristics compared with traditional or even high-performance concrete. Classified as Ultra-High Performance Concrete (UHPC), or Reactive Powder Concrete (RPC). The improved properties of RPC are obtained by improving the homogeneity of the concrete by eliminating large aggregates, increasing compactness of the mixtures by optimizing packing density of fine particles, and using fine steel fibres to provide ductility. The HPC used for nuclear waste containment structures of Indian concrete power plants are having moderate compressive strength, moderate E value, uniform density, good workability, and high durability. There is a need to evaluate RPC regarding its strength and durability to suggest its use for nuclear waste containment structures.

 

REFERENCES  RICHARD P and CHEYREZY M “Composition of Reactive Powder Concrete, Cement and Concrete Research”, 1995, Vol 25  AICTIN P.C. “Cements of yesterday and today: Concrete of tomorrow, Cement and Concrete Research”, 2000, Vol 30.  BLAIS P.Y and COUTURE M. “Precast, Prestressed pedestrian bridge- World‟s first Reactive Powder Concrete structure, PCI journal” 1999,Vol 44  DAURAIC C “Special concrete may give steel stiff competition: Building concrete. The seattle Daily Journal of Commerce”, May 9, 1977.  BASU P.C “Performance requirements of HPC for Indian NPP structure. The Indian  BONNEAU O, VERNET C, MORANVILLE M. and AITCIN P C “Characterization of granular packing and percolation threshold of Reactive Powder Concrete, Cement and Concrete Research” 2000 ,  GOLTERMANN P, JOHNSAN V and PALBOL L “Packing of aggregates: An alternate tool to determine the optimal aggregate mix, ACI Materials Journal”, September – October 1997.  MATTE V and MORANVILLE M “Durability of reactive powder composites: Influence of silica fume on the leaching properties of very low w/b pastes, Cement and Concrete Composites”, 1999, Vol 21.  STAQUET S and EPISON B “Influence of cement and silica fume type on compressive strength of reactive powder concrete, 6th International Sympoium on HPC,University of Brussels Belgium”, 2000.  BICKLEY J.A and MITCHELL D “A state of art review of high performance concrete structures built in Canada”, 1990-2000(2001)  Dili and Santhanam,”The Indian concrete journal”, April 2004  Website on Reactive powder concrete