Intended to provide our own search engines and external engines with highly rich, chapter-representative searchable text on the opening pages of each chapter. Because it is UNCORRECTED material, please consider the following text as a useful but insufficient proxy for the authoritative book pages.
Do not use for reproduction, copying, pasting, or reading; exclusively for search engines.
OCR for page 10
10 Figure 1.3. End zone reinforcement detail used by IDOT. 1.3 Methods and Materials Use of any of these methods depends on the crack width Used for Repair and criteria used by the highway authorities. The following three methods of repair were found in the literature review: 1.3.1 Epoxy Injection Procedure by PCI Manual for the Evaluation and 1. Epoxy injection, Repair of Precast, Prestressed 2. Batching and sealing the cracks, and Concrete Bridge Products 3. Sealing the cracks. The PCI Manual for the Evaluation and Repair of Precast, Prestressed Concrete Bridge Products (11) provides detailed #8 Bar information on the process and steps used in the epoxy injec- tion of cracks in precast, prestressed concrete bridge prod- ucts. The responses to the national survey that was conducted in this research project have shown that this manual is cur- rently used by many state DOTs and precast producers for repair of end zone cracking. Chapter 4 of the PCI publication states that the epoxy injection procedure applies to cracks that are wider than 0.006 in. or to cracks that are noticeable after soaking with water. The publication provides the epoxy injection procedure for two cases (1) cracks accessible and visible from both sides, and (2) blind cracks that are not vis- ible or accessible from both sides. Chapter 5 of the same pub- Elevation End View lication provides information on how to prepare these cracks. Figure 1.4. End zone detail used by Central It also states that 75 psi to 200 psi injection pressure is com- Pre-Mix Prestress Co., Spokane, Washington. monly used for crack widths in the range of 0.006 to 0.007 in.