Static and impact properties of reactive power concrete

Dissertant

al-Nuaymi, Shadha Sadiq Hasan

University

University of Technology

Faculty

-

Department

Department of Building and Construction Engineering

University Country

Iraq

Degree

Ph.D.

Degree Date

2006

English Abstract

A new material known as reactive powder concrete (RPC) is becoming available that differs significantly from traditional concrete.

RPC is characterized by high strength and very low porosity, which is obtained by optimized particle packing and low water content.

The properties of RPC are achieved by : eliminating the coarse aggregates ; just very fine powders are used such as sand, crushed quartz, silica fume or any reactive powders, all with particle size less than 600 micrometers; optimizing the grain size distribution to density the mixture ; heat treatment to improve the microstructure; addition of steel and synthetic fibers (about 2 % by volume); and use super plasticizers to decrease the water to cement ratio.

The main purpose of this research is to study the static properties and impact resistance of the RPC incorporating local powders (reactive silica sand powder) as a pozzolanic material and compare it with RPC incorporating condensed silica fume.

Original RPC-in form of super plasticized cement mixture with powder (reactive silica sand or silica fume ), steel fiber ,and line sand (< 600 mu)- was studied in comparison with modified reactive powder concrete (MRPC) where a natural aggregate (max size 8mm)was used to replace the fine sand of the cementations binder.

The influence of the super plasticizers type, particle size of powder, fine sand type, particle size of fine sand and time of vibration on the performance of RPC-in terms of w / c and compressive strength -was studied.

In the present research work the composition, mix design, compressive strength, flexural strength splitting tensile strength, and static modulus of elasticity of reactive powder concrete and modified reactive powder concrete were studied at various ages of curing and various curing temperatures.

Impact resistance for different ages was also studied.

The results indicated that The Gallium 51 performed better than SP1 or Memento super plasticizers in terms of lower w / c and compressive strength, the sand with particle size less than 300 mu performed better than sand with particle size less than 600 m / i in terms of compressive strength, regardless of the powder type used in manufacturing RPC mixtures.

The results also indicated that it is possible to produce RPC and MRPC from glass sand as a fine aggregate and produce them by using two types of powders.

The results obtained from the present work show that superior properties can be obtained for reactive powder concrete (RPC) and modified reactive powder concrete (MRPC).

Tests indicate that the RPC and MRPC with local powder show enhanced compressive strength, flexural tensile strength, splitting tensile strength, static modulus of elasticity and impact resistance but marginally lower than that produced by using silica fume as pozzolanic admixture.

Results demonstrated that it is possible to produce a concrete of compressive strength up to 172 MPa, flexural strength up to 2.5.3 MPa, static modulus up to 45.95 GPA, and the splitting tensile strength up to 22.9MPa at the age of 28 days.

The impact resistance in terms of the number of blows is 480 with 2.5 cm slab thickness, 1590 with 5cm thickness at 180 days.

Main Subjects

Civil Engineering

Topics

• Concrete

• APA
• MLA
• AMA

Language

English

Data Type

Arab Theses

Record ID

BIM-306250