1. The coarse aggregate should be continuously graded and the fine aggregate should be medium sand.

2、外加剂宜采用缓凝剂、减水剂；掺合料宜采用粉煤灰、矿渣粉等。

2. Retarder and water reducer should be used as additives; Fly ash and slag powder should be used as admixture.

3、机场道面商品混凝土在保证商品混凝土强度及坍落度要求的前提下，应提高掺合料及骨料的含量，以降低商品混凝土的水泥用量。

3. On the premise of ensuring the strength and slump of commercial concrete, the content of admixture and aggregate should be increased to reduce the cement consumption of commercial concrete.

4、水泥应尽量选用水化热低、凝时间长的水泥，优先采用中热硅酸盐水泥、低热矿渣硅酸盐水泥、大坝水泥、矿渣硅酸盐水泥、粉煤灰硅酸盐水泥、火山灰质硅酸盐水泥等。

4. Cement with low hydration heat and long setting time shall be selected as far as possible, and medium heat Portland cement, low heat slag Portland cement, dam cement, slag Portland cement, fly ash Portland cement, pozzolanic Portland cement, etc. shall be preferred.

但是，水化热低的矿渣水泥的析水性比其它水泥大，在浇筑层外表有少量水析出。这种泌水现象，不只影响施工速度，同时影响施工质量。因析出的水聚集在上下两浇筑层外表间，使商品混凝土水灰比改动，而在掏水时又带走了一些砂浆，这样便构成了一层含水量多的夹层，破坏了商品混凝土的粘结力和整体性。

However, the slag cement with low hydration heat has higher water evolution property than other cement, and there is a small amount of water precipitation on the surface of pouring layer. This kind of bleeding not only affects the construction speed, but also affects the construction quality. Due to the precipitation of water gathered between the surface of the upper and lower pouring layers, the water cement ratio of commercial concrete is changed, and some mortar is taken away when water is extracted, thus forming a layer of interlayer with more water content, which destroys the cohesive force and integrity of commercial concrete.

商品混凝土泌水性的大小与用水量有关，用水量多，泌水性大；且与温度高低有关，水完全析出的时间随温度的提高而延长；此外，还与水泥的成分和细度有关。所以，在选用矿渣水泥时应尽量选择泌水性的种类，并应在商品混凝土中掺入减水剂，以降低用水量。在施工中，应及时排出析水或拌制一些干硬性商品混凝土平均浇筑在析水处，用振捣器振实后，再继续浇筑上一层商品混凝土。

The amount of bleeding of commercial concrete is related to the water consumption, which is more than water consumption; The time of complete precipitation of water increases with the increase of temperature; In addition, it is also related to the composition and fineness of cement. Therefore, in the selection of slag cement, the type of bleeding should be selected as far as possible, and water reducing agent should be added into commercial concrete to reduce water consumption. During the construction, it is necessary to drain the water or mix some dry and hard commercial concrete in time, and pour it evenly at the water drainage place, and then continue to pour the upper layer of commercial concrete after vibrating with vibrator.