关于VAE改性砂机械性能,拉力性能,水化热和微观结构的研究

Mortar properties encompass a range of characteristics crucial for construction and masonry work, including workability, water retention, bond strength, durability, compressive strength, volume change, and appearance. Workability refers to mortar's ability to be easily applied and manipulated without sagging or falling off surfaces, which is important for efficient masonry unit placement and alignment. Water retention is essential to prevent the mortar from losing moisture too quickly to...

Strength tests for cement are not performed directly on neat cement paste due to difficulty in obtaining consistent, reliable specimens. Instead, cement is typically tested in the form of cement-sand mortar.
For compressive strength tests, ASTM C 109-05 standards prescribe a cement-sand mix ratio of 1:2.75 and a water/cement ratio of 0.485 for making 2-inch cubes. These cubes are mixed, cast, and cured in saturated lime water at 23°C until testing. Flexural strength testing, outlined in...

The fineness of cement directly influences the rate of hydration, as the hydration begins at the surface of the cement particles. In addition to hydration, the fineness of cement is vital for various properties of concrete including workability, gypsum requirement, and long-term behavior. The fineness of cement is represented in terms of the specific surface of cement which is typically measured in square meters per kilogram, with several methods available for this determination.
Direct...

The Vebe test is a method used to measure the workability of concrete, particularly effective for dry concrete mixes. This test employs a specific apparatus that includes a cylindrical chamber, a standard slump cone, and a transparent disc-shaped rider, all mounted on a vibrating table. The cylindrical chamber has dimensions of nine and a half inches in diameter and eight inches in height.
To conduct the test, concrete is placed into the slump cone. The concrete is filled in layers and...

Mortar, a mixture of Portland cement, hydrated lime, sand, and water, is a crucial binding material in construction. Its primary function is to join masonry units together, filling gaps and ensuring a uniform distribution of weight across the structure. This helps in preventing potential weaknesses. Mortar also serves as a protective barrier against environmental elements such as water and wind, thereby safeguarding the interior of the structure. It also compensates for surface irregularities...

Considering the tensile strength of concrete involves recognizing that the theoretical strength of cement paste can be up to a thousand times higher than what is observed in practical applications. This significant discrepancy is largely attributed to the presence of microscopic cracks within the concrete. These cracks tend to amplify stress at their tips when a load is applied, a phenomenon explained by Griffith's theory of brittle fracture.
The dimensions and shape of a concrete specimen...