Ultraleichte, dünnwandige stabförmige Betonhohlbauteile unter Querkraft- und Torsionsbeanspruchung

桁架杆件可以很好地实现“形式随力”这一理念。因为它们可以以集中和优化的方式根据应力分布进行调整。建筑实践中的例子有二维和空间桁架模型、梁、柱和桅杆结构。目前。这些顶多是用钢建造的。高性能混凝土和创新的钢筋概念的发展为轻型桁架结构越来越多地使用钢筋混凝土开辟了道路。通过考虑自然结构的仿生类比和抽象，可以推进力流优化结构构件的设计。因为它们继承了一种进化的优化。遵循“轻建混凝土”的原则，竹子是超轻的一个辉煌和鼓舞人心的例子。研究了薄壁空心混凝土构件在一般荷载(轴力)作用下的承载能力和变形性能。弯曲、剪切和扭转)是罕见的，只有一些测试证据存在。在SPP1542的第一阶段，研究了薄壁空心钢筋混凝土构件在主要轴力或弯矩作用下的结构性能。结果表明。在材料利用率低、资源利用率要求高的情况下，可以获得较高的承载能力。然而，结构在剪力和扭转作用下的性能仍不清楚。确实是这样。首先，对竹子部分进行的对比试验鼓励了人们对这些荷载情况的希望。仿生的优化可能会带来好的结果。目前，缺乏实验基础来验证非空心混凝土截面中与混凝土保护层大小正好匹配的墙厚度在剪切和扭转下的行为。同样，对薄壁混凝土构件的破坏机理和稳健性研究还不够深入，在这些方面，利用竹子仿生实例的稳定措施可以在系统层面上进行预测，如模压加劲肋或舱壁。这在钢结构中是典型的，但在钢筋混凝土中还不常见。现有的其他组结构构件的设计模型应进行校核和调整，以获得新试验的全面数据。目前，缺乏知识的情况下，不利于在建筑实践中使用超轻空心混凝土构件。为了在SPP1542第一期工程中普遍使用这种空心混凝土构件和构件，有必要对其荷载条件、剪切和扭转进行进一步的理论和试验研究。作为预期的结果，为薄壁混凝土空腹桁架构件在一般荷载条件下的设计、计算和施工奠定了理论和详细的基础。

Truss members can fulfill the idea "Form Follows Force in an excellent way. because they can be adjusted to the distribution of stresses in a concentrated and optimized way. Examples from building practice are two-dimensional and spatial truss models, girders, columns, and mast constructions. Currently. these are erected in steel at most. Developments like high-performance concretes and innovative reinforcement concepts open the way to an increasing use of reinforced concrete for light truss structures.The design of force-flow-optimized structural members can be advanced by taking into account bionic analogies and abstractions of natural structures. because they inherit an evolutionary optimization.Following the principle ''Light Constructions with Concrete", bamboo is a brilliant and inspiring example for ultra-light. thin-walled hollow concrete members.Research to the bearing capacity and deformation behavior of thin-walled hollow reinforced concrete members under general loads (axial force. flexure, shear and torsion) is rare and only some test evidence exists. ln the 1st period of the SPP 1542, the structural behavior of thin-walled hollow reinforced concrete members was investigated under predominant axial force or bending moment. The results show that. one can achieve a high bearing capacity despite a low use of material and high demands on resource-efficiency.Yet, the structural behavior under shear and torsion remains still unclear. Indeed. first comparative tests on bamboo sections encourage hopes that for those load cases. a bionically motivated optimization could lead towards good results.Currently, experimental basics are missing to verify the behavior under shear and torsion for wall thicknesses that just match the size of the concrete cover in non-hollow concrete cross sections. Similarly, failure mechanisms and robustness of thin-walled concrete members are inadequately researched.Under theses aspects, stabilizing measures utilizing the bionic example of bamboo can be anticipated at the system level like molded stiffeners or bulkheads. which are typical for steel construction but not yet common for reinforced concrete. Existing design models for other groups of structural members should be verified and adjusted for the comprehensive data out of the new tests.In the current, missing knowledge stands against the use of ultra-light hollow concrete members in building practice. For general use of such hollow concrete members and constitutive to the works during the 1st period of SPP 1542 further leading theoretical and experimental research on the load conditions shear and torsion becomes necessary. This should be conducted within the frame of the suggested project.As the expected result, then theoretical and detailing foundations will be laid for design, calculation and construction of thin-walled hollow concrete truss members under general loading conditions.