Types of concrete

About: Types of concrete is a research topic. Over the lifetime, 1025 publications have been published within this topic receiving 16656 citations.

Design and Control of Concrete Mixtures

Abstract: This updated, definitive reference book on concrete technology covers the fundamentals and detailed information on freshly mixed and hardened concrete for Canada The properties of concrete as needed in concrete construction are presented, including strength and durability All concrete ingredients are reviewed for their optimal use in designing and proportioning concrete mixtures Applicable standards from the American Society for Testing and Materials, Canadian Standards Association and American Concrete Institute are referred to extensively Individual chapters address: (1) fundamentals of concrete; (2) Portland, blended and other hydraulic cements; (3) fly ash, slag, silica fume and natural pozzolans; (4) mixing water; (5) aggregates for concrete; (6) admixtures for concrete; (7) fibers; (8) air-entrained concrete; (9) designing and proportioning normal concrete mixtures; (10) batching, mixing, transporting and handling concrete; (11) placing and finishing concrete; (12) curing concrete; (13) hot weather concreting; (14) cold-weather concreting; (15) volume changes of concrete; (16) control tests for concrete; (17) high-performance concrete; and (18) special types of concrete

Properties of Concrete at Elevated Temperatures

Abstract: Fire response of concrete structural members is dependent on the thermal, mechanical, and deformation properties of concrete. These properties vary significantly with temperature and also depend on the composition and characteristics of concrete batch mix as well as heating rate and other environmental conditions. In this chapter, the key characteristics of concrete are outlined. The various properties that influence fire resistance performance, together with the role of these properties on fire resistance, are discussed. The variation of thermal, mechanical, deformation, and spalling properties with temperature for different types of concrete are presented.

Smart aggregates: multi-functional sensors for concrete structures—a tutorial and a review

Abstract: This paper summarizes the authors' recent pioneering research work in piezoceramic-based smart aggregates and their innovative applications in concrete civil structures. The basic operating principle of smart aggregates is first introduced. The proposed smart aggregate is formed by embedding a waterproof piezoelectric patch with lead wires into a small concrete block. The proposed smart aggregates are multi-functional and can perform three major tasks: early-age concrete strength monitoring, impact detection and structural health monitoring. The proposed smart aggregates are embedded into the desired location before the casting of the concrete structure. The concrete strength development is monitored by observing the high frequency harmonic wave response of the smart aggregate. Impact on the concrete structure is detected by observing the open-circuit voltage of the piezoceramic patch in the smart aggregate. For structural health monitoring purposes, a smart aggregate-based active sensing system is designed for the concrete structure. Wavelet packet analysis is used as a signal-processing tool to analyze the sensor signal. A damage index based on the wavelet packet analysis is used to determine the structural health status. To better describe the time-history and location information of damage, two types of damage index matrices are proposed: a sensor-history damage index matrix and an actuator–sensor damage index matrix. To demonstrate the multi-functionality of the proposed smart aggregates, different types of concrete structures have been used as test objects, including concrete bridge bent-caps, concrete cylinders and a concrete frame. Experimental results have verified the effectiveness and the multi-functionality of the proposed smart aggregates. The multi-functional smart aggregates have the potential to be applied to the comprehensive monitoring of concrete structures from their earliest stages and throughout their lifetime.

Recycled Concrete as Aggregate for Structural Concrete Production

Abstract: A comparative analysis of the experimental results of the properties of fresh and hardened concrete with different replacement ratios of natural with recycled coarse aggregate is presented in the paper. Recycled aggregate was made by crushing the waste concrete of laboratory test cubes and precast concrete columns. Three types of concrete mixtures were tested: concrete made entirely with natural aggregate (NAC) as a control concrete and two types of concrete made with natural fine and recycled coarse aggregate (50% and 100% replacement of coarse recycled aggregate). Ninety-nine specimens were made for the testing of the basic properties of hardened concrete. Load testing of reinforced concrete beams made of the investigated concrete types is also presented in the paper. Regardless of the replacement ratio, recycled aggregate concrete (RAC) had a satisfactory performance, which did not differ significantly from the performance of control concrete in this experimental research. However, for this to be fulfilled, it is necessary to use quality recycled concrete coarse aggregate and to follow the specific rules for design and production of this new concrete type.