在煤矿道中可持续地使用废弃的道砂,以支持煤矿道的可持续应用

Mortar joint deterioration is a significant concern in masonry structures, with water accumulation in the joints leading to damage from freeze-thaw cycles. The repeated expansion of water during freezing and its melting during thawing develop and propagate cracks in the masonry joints. Eventually, this leads to the spalling of mortar from the joints, loosening masonry units and weakening the structure. The deteriorated mortar joints are also vulnerable to moisture intrusion into the walls.
The...

Preplaced aggregate concrete is ideal for construction environments that are not easily accessible. The process begins by properly wetting the gap-graded coarse aggregates to remove the dirt, then placing it in the form and compacting it. Voids are filled with a mortar mix pumped under pressure through slotted pipes. This mortar typically consists of Portland cement, pozzolan, fine aggregates, water, and a fluidizing aid. The pozzolan helps reduce bleeding and segregation while improving the...

The porosity of concrete is a measure of the void spaces within its structure. These spaces impact its strength and durability significantly. When water and cement interact, a chemical reaction called hydration creates a semi-solid paste. This paste includes combined water, making up approximately 23% of the cement's dry mass, and gel water, which fills minuscule voids known as gel pores, accounting for about 28% of the cement gel volume.
The balance of water to cement in the mix is...

Mortar joints play a critical role in brick masonry, filling the spaces between brick to bind them together and provide structural integrity and strength. The thickness of these joints is variable, typically ranging from less than one-fourth inch to over half an inch, based on structural needs and specific applications.
The process of joint tooling is implemented as the mortar begins to harden. This technique involves compacting and shaping the mortar to enhance both the appearance and the...

The process of manufacturing concrete masonry units begins by mixing stiff concrete composed of Portland cement, aggregates, and water. This mixture is then poured into metal molds. To ensure the concrete settles uniformly and to avoid separation of its components, the mixture in the molds is subjected to vibration. Shortly after, the still-wet blocks are removed from the molds and placed on racks.
These wet blocks are then transported for curing, which can occur in one of two environments: a...

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...