1. Introduction

Ultra-high performance fiber-reinforced cementitious composites (UHPFRCCs) are defined as a concrete matrix that are characterized with a high compression strength of 150–200 MPa, a uniaxial tension strength of 7–15 MPa, and a bending strength of 25–40 MPa [1–3]. UHPFRCC is characterized with a large binder content (cement and silica fume), a large volume of steel fiber, a low water/binder ratio (W/B), and a high microsilica [4]. Accordingly, UHPFRCCs compared with normal concrete (NC) and high-performance concrete (HPC) have become popular in practical applications [5, 6]. UHPFRCCs are more efficient in producing smaller, lighter, and thinner sections due to its superior properties [5, 7].

© 2016 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and eproduction in any medium, provided the original work is properly cited. © 2018 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

On the other hand, an increase in the cement content implies an increase in the overall demand for cement [8, 9], which could be translated into a greater cement production, which correspondingly increases the emission of certain greenhouse gases (CO2, etc.), in addition to increasing the concrete cost as well as the electrical energy consumption [9]. Therefore, UHPFRCC products can be considered as uneconomical construction materials and pose a threat to the environment.

Meanwhile, in the case of sustainability, this type of concrete still needs to be evaluated with regard to their high binder content (especially the cement content) relative to the regularly

Utilization of By‐Product Materials in Ultra High‐Performance Fiber Reinforced Cementitious Composites

http://dx.doi.org/10.5772/intechopen.74376

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The principles applied in UHPFRCC matrix development can be detailed based on previous

1. Removal of coarse aggregate to enhance concrete homogeneity [3]; the recommended mean aggregate size used in producing UHPFRCCs is less than 1 mm and the aggregate-

2. Optimization of granular mixture [1, 3, 27]; ultrafine powder is added for the composition of fine-grained mixture, such as silica fume, fly ash, and so on. Figure 1 shows the physical

• Psozzolanic materials because this substance reacts chemically with calcium hydroxide (Ca(OH)2) that is also written as (CH). These substances produce compounds with cementitious properties (calcium silicate hydrates (C-S-H)/"cement gels"). This finding is reflected automatically by the decrease of porosity in the bulk and particularly in the interfacial zone. These materials improve the mechanical properties of the

3. Decreasing the W/C ratio using high-range water-reducing admixture; this maintains the small spacing of the cement grains, which decreases the space for the interfacial zone

4. Optionally, post-setting heat treatment to enhance mechanical properties of the micro-

5. Optionally, the application of pre-setting pressure for better compaction [1, 28].

used mixtures [25].

• Lubricant,

formation [1].

structure [1, 28].

studies:

3.1. Principles of UHPFRCC composition

cement ratio can be up to 1.4 [21, 26].

effect of ultrafine powder (e.g., silica fume), as

• Filler between the cement particles,

cement paste by reacting with CH.

Figure 1. Ultrafine powder acting as "filler" between the cement particles [1].

Aldahdooh et al. [10] stated that there are several methods that can be employed to reduce the binder content (cement and silica fume) in UHPFRCCs. For example, (i) optimizing the mix design of concrete using mathematical or statistical methods, such as response surface methodology, and so on [11, 12], (ii) utilizing industrial solid wastes and by-products as a supplementary cementitious materials (SCMs) in producing green UHPFRCCs, such as crushed quartz (CQ) [13], fly ash (FA) [14–16], palm oil fuel ash (POFA) [10, 17], recycled glass powder (RGP) [15], activated metakaolin (AM), and ground granulated blast-furnace slag (GBFS) [15, 18, 19].

Nowadays, the utilization of solid wastes is the challenge for engineers to use friendly SCMs produced at a reasonable cost with a low environmental impact. The addition of cost-saving materials by the replacement of a considerable amount of cement reduces CO2 emission during the manufacturer of Portland cement. Moreover, SCMs can improve the majority of fresh and hardened properties of concrete [12, 20].

Based on the above, this review focused on the second method that is particularly dependent on the utilization of wastes and by-products in developing green UHPFRCCs, including their influence on the mechanical properties of UHPFRCCs.
