The subject of the experimental research is concrete with cold-bonded fly ash aggregate from fly ash of Novosibirskaya GRES Thermal Power Plant. Cold-bonded fly ash aggregate has the true specific gravity of 2.50 g/cm{3}, an average density of 1.53 g/cm{3}, water absorption by weight of 18.4 %, and an opened porosity of 28.15 %. Concrete with cold-bonded fly ash aggregate has a compressive strength after 28 days of 37.8 МPa, a flexural strength of 4.9 MPa, an coefficient of linear expansion of 14.8.10-6 K-1 and modulus of elasticity of 18.109 Pa. The water presoaking of lightweight aggregate did not affect the kinetics of heat emission and, consequently, the kinetics of hydration of cement. The shrinkage of concrete with dry aggregate was higher than concrete with presoaking lightweight aggregate. Moreover, the evaporation loss was also less for concrete with dry aggregate. The shrinkage of concrete with presoaking aggregates is much less than the shrinkage of concrete with dry aggregates with the same evaporation loss. The usefulness of presoaking aggregates in working conditions, as “internal curing”, has been confirmed. This will reduce the likelihood of shrinkage cracks during concrete drying.

• Cold-bonded fly ash aggregate concrete
  • 1. Introduction
  • 2. Materials and Methods
    • 2.1. Testing laboratory
    • 2.2. Concrete materials
    • 2.3. Tests of concrete mix components
    • 2.3.1. Determination of grain size of sand
    • 2.3.2. Determination of average density sand grains
    • 2.3.3. Determination of the content of flour and clay particles of sand and clay content in lumps
    • 2.3.4. Determination of normal consistency of cement-water paste and cement setting up time
    • 2.3.5. Determination of sounding of cement
    • 2.3.6. Determination of fineness of cement
    • 2.3.7. Determination of flexural strength and ultimate compressive strength of test cement beam
    • 2.3.8. Assessment of efficiency of superplasticizers
  • 3. Results and Discussion
    • 3.1. Types of tests for cold-bonded fly ash aggregate as an unconventional component of concrete mix
    • 3.2. Physical and mechanical properties of cold-bonded fly ash aggregate
    • 3.3. Сold-bonded fly ash aggregate concrete mix proportion
    • 3.4. Types of testing сold-bonded fly ash aggregate concrete specimens
    • 3.5. Workability of concrete test results
    • 3.6. Concrete specimens test results
    • 3.6.1. Compressive strength
    • 3.6.2. Flexural strength
    • 3.6.3. Coefficient of linear expansion
    • 3.6.4. Modulus of elasticity
    • 3.6.5. Heat emission
    • 3.6.6. Shrinkage of concrete
  • 4. Conclusions
  • 5. Acknowledgement

Magazine of Civil Engineering / Санкт-Петербургский политехнический университет Петра Великого. — Санкт-Петербург: СПбПУ, 2020-. — Периодичность: 8 раз в год. — Выходит с 2020 г. — Загл. с титул. экрана. — Свободный доступ из сети Интернет (чтение, печать, копирование). — Электрон. журнал. — Текст: электронный

Magazine of Civil Engineering / Санкт-Петербургский политехнический университет Петра Великого. — Санкт-Петербург: СПбПУ, 2020-. № 3 (95), 2020. — 1 файл (14,4 Мб). — Свободный доступ из сети Интернет (чтение, печать, копирование). — Электрон. журнал. — <URL:http://elib.spbstu.ru/dl/2/j21-144.pdf>.