Experimental Investigation of an RC Slab Culvert Rehabilitated with Grouted CSPs

The rehabilitation of an existing culvert with corrugated steel plates (CSPs) has been an emerging technology in recent years, but engineers and researchers are not particularly clear about the working principle of the rehabilitated structure. To investigate the mechanical properties of reinforced concrete (RC) slabs rehabilitated with CSPs, laboratory tests were carried out to explore the calculation method and influencing factors of load-carrying capacity of RC slab culverts rehabilitated with grouted CSPs. The results revealed the following: the flexural failure of the prerehabilitated RC slab has little influence on the test-loading capacity of the rehabilitated system; shear failure will occur in the RC slab and grout, and an arch effect will be formed in the CSP and grout after rehabilitation; the higher the shear strength of the concrete of the RC slab and grout, the greater the test-loading capacity of the rehabilitated system: the RC slab and grout greatly contribute to the test-loading capacity of the rehabilitated system; CSP changes the ductility of the rehabilitated system at the failure stage. It was found that the estimation method for the test-loading capacity of the rehabilitated system based on the shear capacities of the RC slab and grout and the flexural capacity of the CSP is reasonable; the maximum difference between the theoretical and experimental results was less than 30%, and the minimum difference between them was 0%.

Test Loading of Structures with a Suspect Resistance

The reliability of load-bearing structures is normally secured through codes, a competent structural design and proper execution inspection. Alternatively, the reliability can be obtained via skilled test loading, which is a feasible technique both in the construction of new structures and in the load-bearing verification of existing ones. Although the current codes lack instructions for test loading, they are, however, used in special cases; for example, when the reliability of the structures is doubtful due to a defect, or when the structure is suspected to have especially high resistance variability. Test loading involves significant research questions that need to be addressed, including: What is the test load in comparison with the expected maximum service time load or the characteristic load? How can the instantaneous test load be compared with the actual long-term service-time load? Does the test loading harm the structure, and what is the target reliability in the test loading calculation? In this paper, we approach these questions from a theoretical point of view and propose how a suitable test load can be chosen in practice using an approximate and a precise approach.

An ultra-stable hafnium phosphonate MOF platform for comparing the proton conductivity of various guest molecules/ions

An ultra-stable PHOS-100(Hf) is reported as an ideal MOF platform for proton conductivity test loading with various guest molecules/ions, as it has excellent chemical and thermal stability.

CREATING A TEST ENVIRONMENT AND HOW TO LOAD TESTS DURING CHIP DESIGN

The article discusses two main stages of the test loading process during chip design: performing the test procedure and copying the main program and running it. A detailed description of the tests is provided. When describing the loading process of the main program, special attention is paid to emergency situations that stop the loading process.

Three-Point Bending Fatigue Test of TiAl6V4 Titanium Alloy at Room Temperature

A polycrystalline alpha-beta TiAl6V4 alloy in the annealed condition was used for the three-point bending fatigue test at frequency f∼100 Hz. The static preload Fstat. = −15 kN and variable dynamic force Fdyn. = −7 kN to −13.5 kN were set as fatigue test loading parameters. The fatigue life S-N curve presented the stress amplitude σa as a function of a number of cycles to fracture Nf. A limiting number of cycles to run out of 2.0 × 107 cycles were chosen for the 3-point fatigue tests of rectangular specimens. In addition, the Smith diagram was used to predict the fatigue life. The alpha lamellae width has a significant influence on fatigue life. It is assumed that the increasing width of alpha lamellae decreases fatigue life. A comparison of fatigue results with given alpha lamellae width in our material to the results of other researchers was performed. The SEM fractography was performed with an accent to reveal the initiation sites of crack at low and high load stresses and mechanism of crack propagation for the fatigue part of fracture.

APPLICATION OF RADIATION PROCESSES FOR TESTING OF GAS TURBINE BLADES

Structural integrity of the gas turbine blades is of great concern. A set of methods and instruments is proposed to study the problems of the test loading of the industrial turbine blades. The approach aims to model the possible hightemperature, shock and irradiation impacts. The test loading is performed using the high-current relativistic electron beam. The developed methodology can be used for test and identification trails of the turbine blades. The experimental bench is designed to assist the thermographic measurements of the temperature dynamics in the blades. It also comprises the corresponding algorithms and software to perform the necessary calculations with.

Failure of a warehouse floor by subsoil settlement

This paper discusses the failure of a warehouse floor (with an approximate surface area of 1.550 m2) inside an industrial building with a total developed area of approx. 8.200 m2 along with the testing of the failure and its repair. Over ten-odd years of operation of the industrial building, its floor was found to develop non-uniform settlement with a maximum depth of approximately 150 mm from the original floor level. The completed survey inspections, geotechnical tests and FEM studies demonstrated that the root cause of these non-uniform settlement events was the foundation of the warehouse floor, built on a subsoil which featured high and long-term deformability. Given the investigated conditions, it was decided to modify the foundation of the new warehouse floor slab by reinforcing the subsoil with drilled micropiling. The calculations completed, test loading of a drilled micropile and on-site inspection of the warehouse flooring in use confirmed that the modification was rational.