1. 1、 Yes, some of the mineral powder mixed in the concrete is the composite technology of mineral powder and fly ash combined with air entraining agent; Under the condition of the same strength, the concrete with mineral powder has the same anti carbonation ability as the ordinary concrete; Under the condition of the same strength and air content, the concrete with mineral powder has the same freeze-thaw resistance as the ordinary concrete. The influence of adding mineral powder on hydration heat, water permeability, chloride ion permeability, carbonation resistance and frost resistance of concrete is studied. The results show that the hydration heat of cement paste can be reced by adding mineral powder into concrete; The water permeability resistance of concrete is greatly improved; It can significantly improve the chloride ion penetration resistance of concrete<
II. Brief introction of concrete:
concrete, referred to as "concrete (T) ó NG) ": refers to the aggregate cemented by cementitious materials into a whole engineering composite. Generally speaking, the term concrete refers to the use of cement as cementing material and sand and stone as aggregate; Cement concrete mixed with water (including admixtures and admixtures) in a certain proportion, also known as ordinary concrete, is widely used in civil engineering.
2. Normal three shift system, a class of two clearance workers, as long as the crane is big, grab big, yard is not a problem, the transport line is fast, then loading and unloading should be fast
3. Whether it is determined as partial shipment mainly depends on whether the goods are loaded on one ship or two ships. If it is the same voyage of the same ship and the goods are loaded on the same ship at both loading ports, it can be regarded as one shipment. Otherwise, it will be regarded as partial shipment.
4. 1. improve proction efficiency, for example: before the birth of the grab crane, the loading and unloading of ore powder at the terminal, 12~16 workers in the warehouse, each shovel, two people in each group, each group holding a large leather net bag, a spade to a large leather net pocket shovel powder, a net bag can reach a maximum capacity of 4 tons of goods. When the net bag is full, it can be lifted up by crane. A warehouse can only dry 200 tons of cargo in 8 hours at most. Nowadays, large ship unloaders can unload more than 2000 tons of ore per hour, which greatly provides proction efficiency
2. To improve proction safety, for example, before the birth of grab crane, 4-6 workers were used in the dock to load and unload logs. First, small steel wire ropes were used to pass through the section gap of log pile to form an estimated area. The two ends of the small steel wire rope were hung on the hook of the crane, and the lifting distance was 1-2m, so that one end of the log was tilted, and then the workers took a 16-28 steel wire rope, There is also a heavy hook at the front end of the wire rope, which is thrown from the neutral gear between the lifted end and the pile. The workers on the other side catch it quickly, otherwise the wire rope will slip into the groove of the pile. The workers who throw the wire rope have to pull up the wire rope and throw it again, or the workers on the other side use the tool with the hook on the long wooden stick to pick up the wire rope, Then the hook is hung on the wire rope to tie up the logs... In this process, the logs may roll and crush the workers' hands and feet, or the workers may bundle more logs and overload, the wire rope will break in the air, and a dozen or dozens of logs will fall into the air, which will kill people. Later, Bao Qifan invented the wood grab, which greatly reced personal injury accidents
5. The size of the material is large, the shape is not standard, and the material will be blocked in the pipe orifice, which needs to be stirred manually from time to time. Changing the vacuum fan may not work. Because the negative pressure will not increase.
6. Transport vessels carrying powder, granular, blocky and other bulk goods. Bulk carriers carry a single kind of cargo and a large quantity of cargo, usually only with a single deck; The hull structure is strong enough to meet the requirements of concentrated load; In order to adapt to cabin operation and improve loading and unloading efficiency, large hatch is adopted; The engine room is usually arranged at the stern of the ship, so that the cargo hold has a spacious continuous space for loading and unloading operations; In order to facilitate rapid loading and unloading, modern bulk carriers of tens of thousands of tons or more are loaded and unloaded by port efficient shore cranes without lifting equipment on board; The cross section of the cargo hold is octagonal, which is convenient for the automatic falling and concentration of the cargo and is concive to the loading and unloading operation. The gross tonnage of bulk carriers is second only to that of oil tankers, and the single ship tonnage can reach more than 100000 tons. In order to meet the requirements of bulk cargo transportation in large quantities, various special bulk carriers have been developed: ① ore carrier. Due to the small stowage factor (the volume of each ton of cargo), the load is too concentrated, and the cargo hold has more than enough volume, the hull structure is made of raised double bottom, the cargo hold is narrow bucket shape, and the hull structure is strong. ② Coal tankers. Good ventilation is provided to prevent coal from heating and spontaneous combustion, and the hull structure is similar to that of ordinary bulk carriers. ③ Bulk grain ship. Due to the large stowage factor, larger tank capacity, dense sinking and fluidity of bulk grain, it is usually necessary to install stop plates to heighten the height of coaming plate on the hatch, so as to make the settled bulk grain suitable for the hatch level. ④ Bulk cement carrier. In order to prevent the cement from caking and flying away, a st collecting chamber or an air filter shall be installed on the hatch cover, which shall be watertight. In addition, there are special bulk carriers for phosphate rock, chemical fertilizer, vehicle bulk cargo and container bulk cargo.
7. It's too complicated. It's hard to make it clear if it's not an expert!
