The core factors to be considered in the selection of Adjustable Screw Jack support materials

The core factors to be considered in the selection of Adjustable Screw Jack support materials 

The material selection of Adjustable Screw Jack support is directly related to the safety,durability and economy of the support system,and needs to be combined with the actual needs of the construction scenario,from the bearing performance,environmental conditions,use characteristics and cost standards and other dimensions of comprehensive judgment,specifically need to focus on the following 6 types of factors:1.Core bearing requirements:matching the load level is the primary principle Bearing capacity is the core function of the top support,which needs to be based on the actual load bearing during construction(including the weight of concrete,the weight of the formwork,Construction personnel and equipment loads,etc.)Choose materials with corresponding strength to avoid deformation or fracture caused by insufficient material strength:

Light load scenario(single jack support bearing≤8kN):For example,for multi-storey civil building floor slab pouring and interior decoration support,choose mild steel(Q235),its yield strength≥235MPa,which can meet the demand for foundation load and lower cost;Medium and heavy load scenarios(bearing 8-12kN):For example,for the construction of high-rise building beams and ordinary bridge abutments,low-alloy high-strength steel(Q355)should be selected,with a yield strength of≥355MPa,and its fatigue resistance is better than that of Q235,which can cope with long-term stress or load fluctuations.Special heavy-duty/impact scenarios(bearing≥12kN or instantaneous impact):For example,for long-span crane beam support in industrial plants and hoisting assistance for prefabricated components,alloy structural steel(45#steel,40Cr)needs to be used.2.Construction environmental conditions:resist environmental corrosion and climate influence The temperature,humidity and corrosive substance content of different construction environments vary greatly,which directly affects the durability of the top support,and it is necessary to choose materials suitable for weather resistance:

Dry indoor environment(such as office interior decoration,factory buildings without humidity requirements):low corrosion resistance,Q235 steel with electrogalvanizing(thin zinc layer but low cost)is sufficient;Outdoor/humid environment(such as rainy season construction,underground garage,waterfront projects):It is necessary to choose rust-resistant materials,and give priority to Q355 steel with thick hot-dip galvanizing(zinc layer≥100μm,rust prevention cycle of 3-5 years)to avoid the decline of bearing capacity caused by long-term moisture and rust of mild steel;Highly corrosive environments(such as coastal projects,chemical plants,pharmaceutical clean workshops):Special materials are required-316 stainless steel(salt spray corrosion resistant)for coastal areas,304 stainless steel(no rust pollution)for pharmaceutical/food workshops,although the cost is high,it can meet the special requirements of the environment.3.Frequency of use and adjustment requirements:related material wear resistance and accuracy The top support may need to be frequently adjusted in height during construction(such as formwork standards),or fixed for a long time,and the appropriate material needs to be selected according to the frequency of use:

Frequent adjustment scenarios(such as the pouring of curved concrete components and projects that require multiple calibration of elevation):The material needs to have high wear resistance and thread accuracy,and preferentially choose 40Cr steel(chrome plating,high surface hardness,less lag during adjustment)or 45#steel(better wear resistance after quenching and tempering than mild steel)to avoid adjustment failure caused by ordinary Q235 steel due to thread wear;Long-term fixed scenarios(such as temporary support for large equipment,beam support that does not require frequent adjustment):low requirements for wear resistance,Q235 steel(paint protection)or cast steel(ZG230-450,suitable for fixed heavy loads),focusing on the static bearing stability of the material.4.Cost and economy:balance performance and budget The procurement cost of different materials varies significantly,and it is necessary to meet safety requirements and combine the project budget to make reasonable choices to avoid excessive pursuit of high performance and cost waste:

Conventional civil projects(such as resettlement housing,ordinary housing):with limited budget and low load/environmental requirements,give priority to Q235 steel(the cost is only 70%-80%of Q355 steel),which is the most cost-effective;Mid-to-high-end projects(such as commercial complexes,municipal bridges):With high requirements for safety and durability,Q355 steel can be used,although the cost is slightly higher,but it can reduce the cost of later maintenance(such as rust prevention treatment)and reduce safety risks;Special customized projects(such as pharmaceutical plants,industrial heavy-duty projects):Stainless steel or alloy structural steel needs to be selected according to mandatory standards,although the cost is high(e.g.,304 stainless steel is 5-8 times that of Q235 steel),but it is a necessary investment to meet project compliance.5.Construction period and durability requirements:Consider long-term use and reusability If the top support needs to be used for a long time(such as rental top support with a large turnover time)or the construction period is long(such as a super high-rise building,the construction period is 2-3 years),the durability of the material should be prioritized to avoid short-term damage and repeated purchase:

Short-term one-time use(such as temporary emergency repair projects,small projects within 3 months):Q235 steel(painted or electro-galvanized)is optional,which can meet the short-term bearing capacity;Long-term reuse scenarios(such as turnover tops of leasing companies,projects with a construction period of more than 1 year):Choose durable materials,such as Q355 steel(thick hot-dip galvanized)or 40Cr steel,which have better fatigue resistance and rust resistance,and can be used multiple times to reduce long-term costs;Permanent support scenarios(such as fixed supports in some industrial plants):cast steel or stainless steel should be used to ensure no rust and deformation during long-term use,avoiding construction troubles caused by later replacement.