Cold weather concreting

✍ Scribed by Krylov, B. A

• Publisher: CRC Press
• Year: 2020
• Tongue: English
• Leaves: 236
• Category: Library

✦ Synopsis

1. Winter Construction -- 1.1. Specific features of winter -- 1.2. Concreting in winter conditions -- 1.3. Problems of winter concreting -- 2. Effects of Frost on the Structure and Properties of Concrete -- 2.1. Modern views on the hardening of concrete -- 2.2. The phase state of water in concrete at different temperatures -- 2.3. The mechanism of deterioration of concrete due to early freezing -- 2.4. Precuring of concrete before freezing -- 2.5. Effects of early freezing on concrete properties -- 2.6. Concrete in the frozen state and its basic properties -- 3. Preparations for Concreting in Winter Conditions -- 4. Concretes Containing Antifreeze Admixtures -- 4.1. The principle of the method and its theory -- 4.2. Selection and assignment of antifreeze admixtures -- 4.3. Procedures -- 5. Thermos Curing -- 5.1. The principle and application of the thermos method -- 5.2. Placement and curing of concrete in structures built on permafrost ground -- 5.3. Curing and cooling of concrete in massive structures -- 6. Electric Contact Heating of Concrete -- 6.1. The principle and application of the method -- 6.2. Heaters for electric contact heating -- 6.3. Heating form works covered with a conductive materials -- 6.4. Application of electric contact heating of concrete -- 7. Electrode Heating of Concrete -- 7.1. Electric conductivity of concrete -- 7.2. Processes in concrete caused by electric current passing through it -- 7.3. Electrodes for electric heating of concrete -- 7.4. Processes at the interface of concrete and an electrode -- 7.5. Electric and thermal fields in electric heating -- 7.6. External mass exchange in electric heating -- 7.7. Electrode heating procedures -- 8. Electric Preheating of Concrete Mixtures -- 8.1. General considerations and the principle of the method -- 8.2. The theoretical background of the accelerated heating of concrete mixtures -- 8.3 Internal heat exchange during the accelerated electric heating of concrete -- 8.4. Changes in plastic properties of concrete caused by accelerated heating -- 8.5. Physico-mechanical properties of concrete subjected to accelerated heating -- 8.6. Equipment for electric preheating of concrete mixtures -- 8.7. Concreting procedures with preheated concrete mixtures -- 8.8. Preheating of concrete mixtures in truck mixers -- 9. Induction Heating of Concrete -- 9.1. The principle and application of the method -- 9.2. Determining basic parameters of heating -- 9.3. Induction heating of concrete in framed structures -- 10. Sealing Joints between Precast Units and between Precast and Cast-In-Place Members in Composite Construction -- 10.1. Specific features of joints between precast concrete units -- 10.2. Erection of precast concrete units -- 10.3. Curing of sealing concrete in joints -- 11. Curing of Cast-In-Place Concrete in Enclosures -- 11.1. The principle of the method and types of enclosures -- 11.2. Curing of concrete in enclosures -- 11.3. Air exchange in enclosures -- 11.4. Concreting in enclosures -- 12. Some Problems of Economics of Winter Concreting -- Appendices -- Specific power values required to heat concrete -- References -- Index.;Concreting in cold weather requires special knowledge and skills to ensure accelerated hardening and high quality in plain- and reinforced-concrete structures. Cold Weather Concreting familiarizes concrete specialists with the characteristic features of concrete in cold weather, including the effects of frost, methods for hardening in subzero temperatures, and other challenges in cold-weather concreting. Both practical techniques and their underlying theories are covered.The book presents many methods for the thermal treatment of concrete by means of electric current--information previously available only in the Russian literature. It presents unique data in the form of diagrams, drawings, and tables, including a chart of the phase state of concretes of different strengths in the process of freezing at different temperatures, the variation of concrete strains in freezing and thawing, and a diagram of electric fields in concrete when electrodes are placed in front of stirrups.

✦ Table of Contents

Cover......Page 1
Title Page......Page 2
Copyright Page......Page 5
The Author......Page 6
Introduction......Page 7
Table of Contents......Page 8
1.2: Concreting in Winter Conditions......Page 10
1.3: Problems of Winter Concreting......Page 11
2.1: Modern Views on the Hardening of Concrete......Page 14
2.2: The Phase State of Water in Concrete at Different Temperatures......Page 19
2.3: The Mechanism of Deterioration of Concrete Due to Early Freezing......Page 22
2.4: Precuring of Concrete Before Freezing......Page 29
2.5: Effects of Early Freezing on Concrete Properties......Page 35
2.6: Concrete in the Frozen State and Its Basic Properties......Page 37
3: Preparations for Concreting in Winter Conditions......Page 48
4.1: The Principle of the Method and Its Theory......Page 54
4.2: Selection and Assignment of Antifreeze Admixtures......Page 60
4.3: Procedures......Page 63
5.1: The Principle and Application of the Thermos Method......Page 68
5.2: Placement and Curing of Concrete in Structures Built on Permafrost Ground......Page 71
5.3: Curing and Cooling of Concrete in Massive Structures......Page 73
6.2: Heaters for Electric Contact Heating......Page 84
6.3: Heating Formworks Covered with a Conductive Materials......Page 101
6.4: Application of Electric Contact Heating of Concrete......Page 106
7: Electrode Heating of Concrete......Page 108
7.1: Electric Conductivity of Concrete......Page 109
7.2: Processes in Concrete Caused by Electric Current Passing Through it......Page 118
7.3: Electrodes for Electric Heating of Concrete......Page 122
7.4: Processes at the Interface of Concrete and An Electrode......Page 130
7.5: Electric and Thermal Fields in Electric Heating......Page 134
7.6: External Mass Exchange in Electric Heating......Page 140
7.7: Electrode Heating Procedures......Page 152
8.1: General Considerations and The Principle of the Method......Page 154
8.2: The Theoretical Background of the Accelerated Heating of Concrete Mixtures......Page 155
8.3 Internal Heat Exchange During the Accelerated Electric Heating of Concrete......Page 158
8.4: Changes in Plastic Properties of Concrete Caused by Accelerated Heating......Page 161
8.5: Physico-Mechanical Properties of Concrete Subjected to Accelerated Heating......Page 166
8.6: Equipment for Electric Preheating of Concrete Mixtures......Page 170
8.7: Concreting Procedures with Preheated Concrete Mixtures......Page 179
8.8: Preheating of Concrete Mixtures in Truck Mixers......Page 181
9.1: The Principle and Application of the Method......Page 184
9.2: Determining Basic Parameters of Heating......Page 185
9.3: Induction Heating of Concrete in Framed Structures......Page 191
10.1: Specific Features of Joints between Precast Concrete Units......Page 194
10.2: Erection of Precast Concrete Units......Page 196
10.3: Curing of Sealing Concrete in Joints......Page 197
11.1: The Principle of the Method and Types of Enclosures......Page 204
11.2: Curing of Concrete in Enclosures......Page 206
11.3: Air Exchange in Enclosures......Page 208
11.4: Concreting in Enclosures......Page 210
12: Some Problems of Economics of Winter Concreting......Page 212
Appendices — Specific Power Values Required to Heat Concrete......Page 214
References......Page 220
Index......Page 224

✦ Subjects

Concrete construction--Cold weather conditions;TECHNOLOGY / Engineering / Civil;TECHNOLOGY / Material Science;Electronic books;Concrete construction -- Cold weather conditions