Many people usually ask how to define heavyweight steel and lightweight steel?There is not unified standard,many experienced designers or project manager usually can't explain very clearly about this,but we could judge some data through overall consideration.
1)Factory crane hoisting weight:≥25tons,we could consider it as heavyweight steel structure;
2)Steel weight per square meter:≥50KG/M²,we could consider it as heavyweight steel structure;
3)Main components steel plate thickness:≥10mm,this is use in lightweight steel structure less.
4)In addition,there are some other reference values,like cost per square meter,max components' weight,max span,structure style,eaves height,etc.All these could offer experienced data to judge factory or warehouse is heavyweight steel or lightweight steel.Of course,in modern construction,there are many buildings including lightweight and heavy weight steel.But some buildings,we could be relatively sure that they are heavyweight steel,like petrochemical facilities,power plants,long span stadium and exhibition center,high rise or super high rise steel structure;
5)Actually there is not heavyweight steel on national norms and technical documents,in order to distinguish the lightweight steel structure houses,so maybe we should call the heavyweight steel as "common steel" will be more suitable.Because common steel structure is widely used and is including various kind of steel structure products.No matter what the size of loading capacity is,common steel structure is also including many contents of lightweight steel structure.Lightweight steel sturcture houses' technology,which is only directing at "light" feature,then has some rules for more specific content;
6)Lightweight steel is also somewhat misty noun,usually there are two understanding way.One is existing "design code for steel structures"(GBJ 17-88),there is "round steel,small angle steel lightweight steel structure",which is meaning lightweight steel structure use round steel and less than L45*4 and L56*36*4 angle steel.And mainly it's in the time that was being lack of steel.And this kind of steel sturcture right now is by and large cancelled.Another is on "Technical specification for steel structure of light-weight buildings with gabled frames (CECS102:2002)",which is provided with light roof and light wall (also can conditionally use masonry walls) of the single solid web portal rigid frame structure,here the lightweight type is mainly meaning the retaining steel products,which is lighweight material.Since the former has been cancelled, so now the meaning of the light steel is mainly refers to the latter one.
7)Thus, lightweight steel and heavyweight steel,there is not the weight of the structure itself,it's under the weight of the enclosure material, and on the structural design concept is consistent.