This paper proposes novel concrete interlocking blocks made of fly ash and GGBS which are an alternative for the conventional concrete blocks. The artificial neural network (ANN) technique is used to estimate the mechanical strength of interlocking blocks and is verified with experimental investigation. The ANN model is based on the Levenberg–Marquardt principle which is executed using MATLAB. The inputs are given in the percentage ratio of cement: fly ash: crushed stone aggregate (FA): coarse aggregate (CA) for the process of learning, testing, and validation. The selected model is subjected to several trials in terms of mean square error, containing 4 input, 2 sets of 10 hidden layers, and one output components. In this study, a total of 2600 blocks of different mixes were tested as per IS 2185-1 (2005) to assess 3, 7, 14, 21, and 28 days’ strength. The experimental investigations were carried out in two phases. In the first phase, experimental investigations to identify the optimum mix proportions of cement, aggregate, fly ash, and ground granulated blast furnace slag to achieve desired compressive strength was carried out. In the second phase, the identified mix proportions were analysed using ANN to predict the compressive strength of interlocking blocks. The results indicate that the proposed ANN model developed to determine the mechanical strength and cost of interlocking blocks has excellent prediction ability.

Spirally welded tube (SWT) members are predominantly used for offshore oil and gas transportation in the pipeline industry. The use of SWTs in construction is gaining attention with emerging and qualitative research. SWT columns have no parametric limitation in manufacturing. However, no specific research is available for the influence of helix angle in SWT columns as structural member. This investigation stresses on understanding the behavior of SWT columns with different helix angles. Seventy-two finite element (FE) models of SWT columns have been analyzed to study the influence of length to diameter (L/D) ratio, diameter to thickness (D/t) ratio and helix angle on the load-carrying capacity. Test results of two SWT columns available in the literature are used for validating the developed FE model. In addition, the capacity of the columns based on standard codes is computed and compared with the FE results. All the columns are axially compressed and the buckling and post-buckling behavior are simulated. Initial stiffness and ductility index of the columns are discussed. Helix angle between 40° to 50° are found to show the best results.