求翻译：d．现浇段砼石子粒径不大于2cm，混凝土强度宜比预制梁板高5Mpa，混凝土按设计和规范要求掺高效减水剂和微膨胀剂。是什么意思？

d. In-situ concrete gravel size segment is not greater than 2cm, prefabricated flat-slab concrete strength should be higher than 5Mpa, according to the design and specifications of concrete superplasticizer and mixed micro-expanders.

[object Object]

The d. cast-in-place section tong gravel particle size is not bigger than 2cm, the concrete intensity suitably compared to prefabricates Liang Bangao 5Mpa, the concrete mixes the highly effective water reducing agent and the micro plumping agent according to the design and the standard request.

d． Particle size is not more than 2cm in-situ concrete stones, concrete strength should be higher than that of precast beam slab 5Mpa, according to requirements of design and specification of concrete with high range water reducing agent and expansive agent.

d. In-situ concrete gravel size segment is not greater than 2cm, prefabricated flat-slab concrete strength should be higher than 5Mpa, according to the design and specifications of concrete superplasticizer and mixed micro-expanders.