1. Requirements and treatment of formwork

模板有木模板和钢模板两种。使用前要将模板面清理干净，不得粘有干硬水泥砂浆等杂物。木模板要用清水充分湿润和清洗，不留积水，要使模板缝隙拼接严密。在浇筑商品混凝土时，我们应当时刻关注模板、支架、堵缝等，当我们发现模板发生移动的时候，应当马上停止浇筑，并且应当尽快维修好。

There are two kinds of formwork: wood formwork and steel formwork. The formwork surface shall be cleaned before use, and no dry hard cement mortar and other debris shall be adhered. The wood formwork shall be fully wetted and cleaned with clean water, without ponding, and the formwork gap shall be tightly spliced. When pouring commercial concrete, we should always pay attention to the formwork, support, caulking, etc. when we find that the formwork moves, we should immediately stop pouring and repair it as soon as possible.

拆除模板应当考虑不承重模板和承重模板的具体情况进行，不能一概而论，对于非承重模板，当商品混凝土的强度达到2.5MPa以后，此时就导致商品混凝土达到不因拆除模板二次发生倒塌的情况，这个期限大约为3～4天。对于承重模板的拆除日期，一般当商品混凝土达到强度的70％时方可拆除，要防止过早拆模。

For the non bearing formwork, when the strength of commercial concrete reaches 2.5MPa, the commercial concrete will not collapse again due to the removal of formwork. This period is about 3-4 days. For the removal date of load-bearing formwork, it can be removed only when the commercial concrete reaches 70% of the strength. It is necessary to prevent premature removal of formwork.

2.商品混凝土的搅拌

2. Mixing of commercial concrete

商品混凝土的上料顺序为：我们将是石子、水泥和砂按比例装入料斗里。然后再鼓筒内加上水，也可以在料斗进行进料的时候加上水。这样就可以保障在料斗将料装入鼓筒内时，水泥可以夹在砂子和石子之间，这样可以达到就很好的效果。同时，在搅拌商品混凝土时，要严格控制它的配合比是关键，要经常进行检查，从而就可以保证材料的计量很准确。

The feeding sequence of commercial concrete is as follows: first, we will load stones, cement and sand into the hopper in proportion. Then add water into the drum, or add water when the hopper is feeding. In this way, the cement can be sandwiched between sand and stone when the hopper loads the material into the drum, which can achieve good effect. At the same time, in the mixing of commercial concrete, to strictly control its mix proportion is the key, to often check, so as to ensure that the measurement of materials is very accurate.

此外，我们还要注意一些外加剂的特性和品质情况，从而使我们可以合理的控制外加剂。促使商品混凝土的搅拌比较的均匀。达到这样的效果，就必须做到商品混凝土的搅拌时间不能太长，如果时间较长的话，就会导致商品混凝土的和易性降低，这样就会导致拌合机的效率大打折扣了。

In addition, we should also pay attention to the characteristics and quality of some admixtures, so that we can reasonably control the admixtures. Promote the mixing of commercial concrete more uniform. To achieve this effect, the mixing time of commercial concrete must not be too long. If the mixing time is too long, the workability of commercial concrete will be reduced, and the efficiency of mixer will be greatly reduced.

3.商品混凝土的浇筑

3. Pouring of commercial concrete

商品混凝土必须在发生凝结前进行浇筑，如果浇筑前，商品混凝土发生凝结的话，我们可以给它再进行一次搅拌，从而恢复到原来的状态。在浇筑商品混凝土前，如果出现了商品混凝土离析的情况的话，我们也要对商品混凝土进行重新搅拌，这样才能够进行浇筑。在浇筑商品混凝土的时候，为了使其不发生离析的现象，我们应当保证商品混凝土的倾落高度不超过2m。

Commercial concrete must be poured before setting. If commercial concrete sets before pouring, we can mix it again, so as to return to the original state. Before pouring the commercial concrete, if there is segregation of the commercial concrete, we also need to re mix the commercial concrete, so that the pouring can be carried out. When pouring commercial concrete, in order to avoid segregation, we should ensure that the falling height of commercial concrete is not more than 2m.

在进行楼板的商品混凝土浇筑时，要保证商品混凝土的倾落不超过lm。商品混凝土的倾落如果超过了这些高度，我们就要采取串筒、溜槽等措施来进行下料。所用的溜槽通常是由木板钉成，在它的表面包上铁皮，在使用溜槽时它的倾角不得超过30度。串筒主要是由薄钢板制成的，每节筒长70cm左右，使用的是钩环的方式进行连接，筒内还装有缓冲挡板。同时，应该分层进行商品混凝土的浇筑，做到随浇随捣。

When pouring the commercial concrete of the floor, it is necessary to ensure that the fall of the commercial concrete does not exceed LM. If the fall of commercial concrete exceeds these heights, we should take measures such as tumbling barrel, chute and so on. The chute used is usually made of wood nailed, and its surface is covered with iron sheet. When using the chute, its inclination angle shall not exceed 30 degrees. The tandem cylinder is mainly made of thin steel plate, and each cylinder is about 70cm long. It is connected by hook and loop, and buffer baffle is installed in the cylinder. At the same time, the commercial concrete should be poured layer by layer, so that it can be poured and tamped at the same time.