Małek Marcin, Kadela Marta, Terpiłowski Michał, Szewczyk Tomasz, Łasica Waldemar, Muzolf Paweł
Faculty of Civil Engineering and Geodesy, Military University of Technology in Warsaw, ul. Gen. Sylwestra Kaliskiego 2, 00-908 Warsaw, Poland.
Building Research Institute (ITB), ul. Filtrowa 1, 00-611 Warsaw, Poland.
Materials (Basel). 2021 May 23;14(11):2760. doi: 10.3390/ma14112760.
The amount of steel chips generated by lathes and CNC machines is 1200 million tons per year, and they are difficult to recycle. The effect of adding steel chips without pre-cleaning (covered with production lubricants and cooling oils) on the properties of concrete was investigated. Steel waste was added as a replacement for fine aggregate in the amounts of 5%, 10% and 15% of the cement weight, which correspond with 1.1%, 2.2% and 3.3% mass of all ingredients and 0.33%, 0.66% and 0.99% volume of concrete mix, respectively. The slump cone, air content, pH value, density, compressive strength, tensile strength, tensile splitting strength, elastic modulus, Poisson's ratio and thermal parameters were tested. It was observed that with the addition of lathe waste, the density decreased, but mechanical properties increased. With the addition of 5%, 10% and 15% metal chips, compressive strength increased by 13.9%, 20.8% and 36.3% respectively compared to plain concrete; flexural strength by 7.1%, 12.7% and 18.2%; and tensile splitting strength by 4.2%, 33.2% and 38.4%. Moreover, it was determined that with addition of steel chips, thermal diffusivity was reduced and specific heat capacity increased. With the addition of 15% metal chips, thermal diffusivity was 25.2% lower than in the reference sample, while specific heat was 23.0% higher. No effect was observed on thermal conductivity.
车床和数控机床每年产生的钢屑量为1.2亿吨，且难以回收利用。研究了添加未经预清洗（覆盖有生产润滑剂和冷却油）的钢屑对混凝土性能的影响。以钢屑替代细集料，替代量分别为水泥重量的5%、10%和15%，分别相当于所有成分质量的1.1%、2.2%和3.3%，以及混凝土混合料体积的0.33%、0.66%和0.99%。测试了坍落度、含气量、pH值、密度、抗压强度、抗拉强度、劈裂抗拉强度、弹性模量、泊松比和热参数。结果表明，添加车床钢屑后，密度降低，但力学性能提高。与普通混凝土相比，添加5%、10%和15%的金属屑时，抗压强度分别提高了13.9%、20.8%和36.3%；抗弯强度分别提高了7.1%、12.7%和18.2%；劈裂抗拉强度分别提高了4.2%、33.2%和38.4%。此外，还确定添加钢屑后，热扩散率降低，比热容增加。添加15%的金属屑时，热扩散率比参考样品低25.2%，而比热容高23.0%。未观察到对热导率有影响。
