Development of concrete from lignite fly ash aggregates | |
| Author | Karki, Arjun Kumar |
| Call Number | AIT Thesis no. ST-97-14 |
| Subject(s) | Aggregates (Building materials) Fly ash |
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering. |
| Publisher | Asian Institute of Technology |
| Series Statement | Thesis ; no. ST-97-14 |
| Abstract | Fly ash aggregate concrete (F AAC) is produced from artificially manufactured three classes of fly ash aggregates (FAA) and is a light weight concrete. Mechanical properties such as compressive strength, splitting tensile strength, flexural strength and modulus of elasticity, and durability such as drying shrinkage and abrasion resistance of F AAC are evaluated from laboratory experiments. The compressive strength and modulus of elasticity of mortar having same w/c ratio as that ofFAAC are also determined from the laboratory tests. The tensile strength of FAA is computed from point load test making use of theory of elasticity. The compressive strength of FAA is determined from application of two phase model ofFAAC. There exists a certain definite relationship between compressive strength and tensile strength for any homogeneous elastic solid. Hence, the expression for the compressive strength of FAA is finally derived from the the plot between compressive strength of FAA obtained from two phase application and the tensile strength of FAA. The compressive strength computed from this expression is made use of in two phase model of F AAC and compressive strength of F AAC is computed. The compressive strength of F AAC computed from the model and obtained from the tests are found to be almost identical. Likewise, the modulus of elasticity of F AAC computed from two phase model and obtained from tests are almost the same. The equations giving the relationships between (a) flexural strength and compressive strength, (b) tensile strength and compressive strength and (c) modulus of elasticity and compressive strength given by ACI manuals for conventional concrete (CC) are either conservative or almost identical to those ofFAAC. Hence all the relationships for mechanical properties of conventional concrete given by ACI manuals can be used for F AAC also. The drying shrinkage and abrasion resistance of F AAC are compared with those of CC having same w/c ratio and ratio of paste volume to volume of voids of binary mixture of sand and coarse aggregates. The drying shrinkage of F AAC is higher than that of CC. The abrasion resistance is higher for the FAAC of higher compressive strength. F AAC having compressive strength upto 400 kgf/cm2 can be produced. F AAC could be a better alternative to conventional concrete where the weight is of prime concern. Thus, the development of F AAC would provide an alternative to the rapidly depleted natural aggregates and also result in easier and environmentally safer way of handling of fly ash. |
| Year | 1997 |
| Corresponding Series Added Entry | Asian Institute of Technology. Thesis ; no. ST-97-14 |
| Type | Thesis |
| School | School of Engineering and Technology (SET) |
| Department | Department of Civil and Infrastucture Engineering (DCIE) |
| Academic Program/FoS | Structural Engineering (STE) /Former Name = Structural Engineering and Construction (ST) |
| Chairperson(s) | Wijeyewickrema, Anil C. |
| Examination Committee(s) | Somnuk Tangtermsirikul;Pichai Nimityongskul;Niwa, Junichiro |
| Scholarship Donor(s) | Asian Institute of Technology Partial Scholarship |
| Degree | Thesis (M. Eng.) - Asian Institute of Technology, 1997 |