In-Situ Testing Research Articles

Principle of Common Lab and In-Situ Testing With the Quality Control and the Case Studies

Testing building materials is essential for ensuring quality control in the construction field. In order to meet the necessary standards, codes, and specifications, it should adhere to the rules in the appropriate way. Soil, aggregate, and concrete are typically the materials tested. Aggregate testing, which is covered by BS 812, may also be tested in accordance with BS 1377, which regulates soil testing, to determine the particle size distribution. In accordance with the size of the soil, BS 1377 also provides standard guidelines on the test procedure for Proctor compaction. The Archimedes principle is used to determine the density by measuring the displacement of water or a related material, such as paraffin oil or sand. Moreover, the determination of the compressive strength of the concrete is regulated by BS EN 12390. The sampling procedure, standard procedure of the Proctor compaction test, visual evaluation of the compressive strength test failure modes, and the in-situ core should all be examined as described in this paper in order to guarantee the testing's high quality. The last section includes four common case studies in construction connected by the faulty cube-making process, the inconsistent compressive strength result, and the lack of coordination of construction activities. In conclusion, construction material testing is an integral part of quality assurance in construction, but it should be conducted in accordance with the standards to ensure that the materials have the necessary characteristics and properties to perform as intended.

Transforming the Testing and Evaluation of Autonomous Multi-Agent Systems: Introducing In-Situ Testing via Distributed Ledger Technology

Transforming the Testing and Evaluation of Autonomous Multi-Agent Systems: Introducing In-Situ Testing via Distributed Ledger Technology

Prior austenite grain measurement: A direct comparison of EBSD reconstruction, thermal etching and chemical etching

It is well known that the prior austenite grain (PAG) microstructure of steels has a significant impact on their microstructure evolution and mechanical properties. Many PAG measuring techniques have been developed over many decades, with the effectiveness of each varying alloy-to-alloy. Some of the more common techniques, specifically for bainitic and martensitic grades, are thermal etching and picric acid etching, which both involve the preferential etching of PAG boundaries in order to reveal the austenitic microstructure. More recently, parent grain reconstruction techniques using EBSD (electron backscatter diffraction) mapping have shown good promise in recreating PAG microstructures from BCC-FCC orientation relationships, and can now be deployed at speed with the advent of rapid detectors (1000s of pixels per second). This study aims to compare the accuracy and relative advantages/disadvantages of picric acid etching, thermal etching and EBSD reconstruction methods. A TESCAN and NewTec In-Situ Testing (TANIST) capability was used to directly observe and measure the true high-temperature PAG structure during the austenitisation of SA-540 B24 low alloy steel. These high-temperature PAG measurements were then compared to measurements from the same area obtained using thermal etching, picric acid etching and EBSD parent grain reconstructions after quenching to room temperature. Reconstructing the parent austenite grains from EBSD data resulted in the closest measurement of PAG size. PAG boundaries were delineated well by thermal etching but surface effects (such as surface relief and ghost traces) created complexities when identifying the exact position of boundaries. Picric acid etching, which produced the least accurate measurement, was found to reveal PAG boundaries well, however it was limited by its ability to sufficiently etch annealing twin boundaries and its susceptibility to microsegregational effects. EBSD reconstruction and thermal etching were more consistent at reconstructing/revealing these boundaries, although inaccuracies with the techniques were still observed.

Experimental Investigation and In-Situ Testing of Traffic-Induced Vibrations on the Adjacent Ruins of an Ancient Cultural Sites

Background: Studying the effects of traffic vibration on adjacent structures has produced fruitful results, but there is a lack of systematic research on the protection, assessment, and ambient vibration effects on cultural relics, and the majority of the studies focus on above-ground buildings, with less research conducted on underground cultural relic sites. Objective: In order to investigate the effects of road-traffic-induced vibration on nearby underground sites, the distance between them was precisely determined. Methodology/approach: The site of Chengshang Village in Jurong City, Nanjing, China, was chosen as the research object, and the vibration of the underground site caused by traffic volume was measured on-site. Based on statistical analysis of experimental data, the vibration velocity was deduced as a function of the vehicle’s speed and the vibration source’s distance. Results: The excellent frequency band for traffic load vibration is between 0 and 40 Hz, and the attenuation speed of high-frequency vibration is faster than that of low-frequency vibration; the vibration speed is positively correlated with the speed of the vehicle, and the distance from the vibration source is exponentially attenuated; and under the condition of the determined limit value of the load and the vibration speed, the safety distance increases. Conclusions: This research utilizes the collected data to describe the relationship between the vibration velocity and the distance from the vibration source. Additionally, it estimates the appropriate distance at which cultural relics should be placed from the road to ensure their safety. The study’s findings may serve as a valuable point of reference for traffic planning and the preservation of underground cultural monuments.

In-Situ Testing Techniques for Mechanical Properties of Materials: Development and Applications

In-Situ Testing Techniques for Mechanical Properties of Materials: Development and Applications

Multifunctional In-Situ Testing Device for Investigating the Service Performance of Materials

To obtain the change rule of material/structure service performance under complex working conditions, this study developed a material/structure mechanical property testing device with multi-load and multi-physics loading functions. The features of this device include its ability to realize the composite mechanical loading of three loads (tension/compression–bending–torsion), as well as physical field loading, such as current field, magnetic field, and thermal field, to realistically simulate the actual service conditions of materials/structures. To monitor the surface topography change, temperature, and strain distribution of the specimen in real-time, various in-situ monitoring methods, including microscopic imaging, infrared thermal imaging, and digital image correlation method, were integrated into the device. To realize multi-load composite loading, a six-degree-of-freedom parallel drive platform was adopted in the device, and its control system was developed with a distributed double-layer structure to realize the closed-loop control of any combination of load forms. All functional modules of the device were calibrated, and a coaxial calibration method based on a six-dimensional force sensor was proposed. Lastly, several tests were performed to evaluate the effectiveness of the proposed device functions, and the test results revealed the broad application prospects of the device.

Compressive Strength Assessment of Normal and Self-Compacting Concrete Made with Recycled Coarse Aggregate Using In-Situ Tests

There is an increasing trend in construction for using recycled coarse aggregate (RCA) concrete, which is a more sustainable approach for reducing natural resource consumption. One typical method for developing more environmentally friendly structures is to partially substitute natural aggregate. limited studies investigated the use of in-situ tests to assess the compressive strength of concrete made with RCAs. In this study, ultrasonic pulse velocity (UPV) and core sampling (CST) tests were used to evaluate the compressive strength of normal vibrated (NVC) and self-compacting (SCC) concretes made with recycled coarse aggregates (RCAs). Four different compressive strengths ranging from 25 to 55 MPa were adopted for each concrete type to consider the effect of replacing 0, 20%, 40%, 60%, 80%, and 100% of the required natural coarse aggregates (NCAs) with (RCAs). Exponential relationships were adopted to relate the UPV values with the compressive strength for both RCA-NVC and RCA-SCC. Also, suggested factors were adopted to correct equivalent core strengths for both RCA-NVC and RCA-SCC. The results of both test methods (UPV) and (CST) showed good correlations to estimate the compressive strength of RCA-NVC and RCA-SCC with confidence limits of 93%.

In-Situ Test Method for Hydrodynamic Characteristics of Water Flowing Around Piles

The dynamic characteristics of the flow around the pile directly determine the distribution law of the force of the flow on the pile, which is the basis of the calculation of the flow load of the hydraulic structure. At present, the model test and numerical simulation methods are mainly used to study the flow characteristics around the pile. There are problems of model scale effect and test accuracy in the laboratory model test, and inherent problems in the numerical simulation method, such as the determination of medium parameters, mesh division, and boundary conditions. Therefore, the research results cannot reflect the actual situation of the interaction between water flow and pile. This paper developed a field test system for measuring the hydrodynamic pressures on surface of piles which are the vital foundations of wharves under superhigh Reynolds number. And the analysis methods of in-situ data, which can realize the multifunction including calibration and transformation for test data, frequency and time-domain statistical analysis process, were put forward according to the theory of stationary random process and mathematical statistics method. A representative frame wharf located in the upper reaches of the Yangtze River was performed as a case study, and the developed system was utilized to operate the in-situ test on this practice. Application showed that the field test system and the analysis methods can be applied to obtain the more accurate distribution of the pile surface hydrodynamic pressure. And the drag coefficient in wharf field ranged from 0.30 to 0.40. These findings in this paper may provide significant technical support for the in-situ test in similar structures and some reference for drag force calculation of flow around pile in the engineering design.

Characterization and In-Situ Test of Mechanical Properties of MEMS-Based Inertial Delay Slider Mechanism

This paper proposed a method for the in-situ characterization of force applied to the MEMS-based inertial delay slider mechanism. The mechanism mainly includes MEMS W-type spring, sliding gear guide structure, card pin, etc. The force applied on the mechanism, including the spring force, the friction force between the slider and the sliding gear, and the final clamping force could be measured in a single run. According to the measuring result, the calculated spring force and clamping force coincides with the experimental result. In this way, the model for the dynamic process could be validated and modified for an effective description of the operation of the mechanism.

GTN Model-Based Material Parameters of AZ31 Magnesium Sheet at Various Temperatures by Means of SEM In-Situ Testing

Magnesium alloys are primarily associated with complex forming mechanisms, which yield ductility at high temperatures. In sheet metal forming, high triaxiality stress states that favor the ductile damage mechanisms of void formation and growth are known to malleable metals. The formulation of coupled damage models has so far failed, due to the incomplete experimental determination of damage parameters for magnesium AZ31 thin sheet. A quantitative investigation was conducted to determine the ductile damage behavior of twin-roll cast, hot rolled, and annealed AZ31 thin sheet. Results on the mechanisms of void nucleation-, coalescence- and growth-rate were established at temperatures ranging from room temperature to 350 °C. In-situ tensile tests were carried out in a scanning electron microscope with three different specimen types: Simple tension specimens, notched specimens for high triaxiality stress state testing, and shear specimens. Through a comparative analysis of local strains measured by digital image correlation and local void volume fractions determined through post-mortem analysis of specimen cross-sections, GTN (Gurson–Tvergaard–Needleman) model-based material parameters were determined by experiment, representing a novel departure in the magnesium research landscape. The procedure developed in this context should also be transferable to other metals in the form of thin sheets.

Evaluation of Ultimate Bearing Capacity of Pre-Stressed High-Strength Concrete Pipe Pile Embedded in Saturated Sandy Soil Based on In-Situ Test

Estimation of ultimate bearing capacity (UBC) of pre-stressed high-strength concrete (PHC) pipe pile is critical for optimizing pile design and construction. In this study, a standard penetration test (SPT), static cone penetration test (CPT) and static load test (SLT) were carried out to assess, determine and compare the UBC of the PHC pipe pile embedded in saturated sandy layers at different depths. The UBC was calculated with three methods including the JGJ94-2008 method, Meyerhof method and Schmertmann method based on in-situ blow count (N) of SPT (SPT-N) which was higher than the values recommended in survey report regardless of pile length. The average UBC values calculated with cone-tip resistance and sleeve friction from CPTs was also higher than the value recommended in the survey report. Moreover, the actual UBC values directly obtained by load-displacement curves from SLTs were in line with the calculated values based on in-situ SPTs and CPTs, but approximately twice as high as the values recommended in the survey report regardless of pile length. For the SPT method, the application of bentonite mud in saturated sand layers is critical for the assessment of pile capacity in the survey phase, CPTs can provide reliable results regardless of soil characteristics and groundwater if the soil layer can be penetrated, and SLTs are necessary to accurately determine the UBC in complex stratum.

Laboratory and In-Situ Testing of Integrated FBG Sensors for SHM for Concrete and Timber Structures.

Long-term structural health monitoring (SHM) plays an important role in the safety of public transport infrastructure such as bridges or tunnels and warns in the event of any emerging problem. This article describes development and testing of system based on fiber Bragg grating (FBG) sensors that can detect changes in strain and temperature. The first phase of the research has been focused on the development of new fiber optic sensors for the monitoring of concrete structures and their investigation in laboratory conditions. The work also shows novel applicability of the same FBG technology for glulam structures. Mechanical loading tests of the concrete beam as well as glulam beam with embedded sensors were carried out. Data measured by developed fiber optic sensors were compared with the readings from reference sensors as well as with the analytically calculated values. The achieved results proved good agreement between the measured data, analytical data and reference methods. In second phase of the research, the pilot installation of the sensors was carried out on the newly constructed prestressed-concrete bridge. The bridge was monitored throughout pre-stressing phase and monitoring continued after the completion of the construction works. Problems with the fragility of the sensors occurred during the measurements, but the obtained results provide a good basis for further improvement of the system.

三轴搅拌桩施工挤土效应的试验研究

三轴搅拌桩施工挤土效应的试验研究

(Invited) Hydrogen Overview and AWSM Project Updates

HydroGEN (https://www.h2awsm.org/) Energy Materials Network (EMN) a Fuel Cell Technologies Office (FCTO) consortium that aims to accelerate the discovery and development of advanced water splitting materials (AWSM) for sustainable, large-scale hydrogen production, and to more effectively enable the widespread commercialization of hydrogen and fuel cell technologies, in line with the H2@Scale initiative (https://www.energy.gov/eere/fuelcells/h2-scale), and meet the ultimate cost target for production set by the U.S. Department of Energy (DOE) at $2/kg H2. HydroGEN EMN is a six national laboratories consortium comprises National Renewable Energy Laboratory (NREL) - lead, Lawrence Berkeley National Laboratory (LBNL), Sandia National Laboratory (SNL), Lawrence Livermore National Laboratory (LLNL), Idaho National Laboratory (INL), and Savannah River National Laboratory (SRNL). With the rollouts of fuel cell electric vehicles (FCEVs) by major automotive manufacturers underway, enabling AWS technologies for the widespread production of affordable, sustainable hydrogen becomes increasingly important. The HydroGEN Consortium offers more than 80 materials capabilities nodes to help address RD&D challenges in efficiency, durability and cost. The capabilities span computational tools and modeling, materials synthesis, characterization, process manufacturing and scale-up, and analysis. Detailed descriptions of all the HydroGEN nodes are available in a searchable format on the HydrogGEN website (https://www.h2awsm.org/capabilities), including information such as the host National Lab, the capability experts, and a synopsis of the node’s unique aspects and capability bounds. By design, the nodes are cross-cutting, and any given node may be useful for one or several advanced water splitting (AWS) technologies. Leveraging the HydroGEN consortium’s staff of technical experts and broad collection of resource capabilities is expected to advance the maturity and technology readiness levels in all the AWS technologies, including low- and high-temperature electrolysis, photoelectrochecmical (PEC) and solar thermochemical (STCH) routes, which includes hybridized thermochemical and electrolysis approaches to water splitting. Currently, there are 20 HydroGEN seedling projects, and one project focused on benchmarking advanced water splitting technologies. These 21 new projects utilized over 40 unique capabilities across the six HydroGEN core labs. HydroGEN is indeed a national innovation ecosystem that comprises 11 national labs, 7 companies, and 30 universities. The experimental and computational data generated within HydroGEN are stored and shared within and across projects within the secured HydroGEN Data Hub (https://datahub.h2awsm.org/), which currently comprises 128 users and 3889 data files. The goal is to make the digital data generated within HydroGEN accessible, so the data can be shared and leveraged throughout the EMNs and in future programs. This presentation will provide an overview of the HydroGEN EMN consortium and highlight some low temperature water electrolysis projects. Proton Onsite met and exceeded near-term performance targets of 1.85V (achieved 1.8 V) at 2.0 A/cm2, using Proton-synthesized high activity IrRu oxide catalysts of different compositions. The Proton PEM water electrolysis cell also demonstrated 800 hours of durability at 2 A/cm2, operating at 80°C and 30 bar. This project utilized NREL’s ex-situ characterization node towards a better understanding of IrRu oxide catalysts stability. Proton’s improved cell efficiency is a step towards achieving its PEM water electrolysis cell efficiency goal of 43 kWh/kg (1.7 V at 90°C) and at a cost of $2/kg H2.Collaboratively, LANL, SNL, and NREL demonstrated promising alkaline exchange membrane water electrolysis performance, comparable to iridium oxide, using SNL Anion Exchange Membrane node, LANL-developed PGM-free oxygen evolution reaction perovskite catalyst, and NREL’s expertise in membrane electrode assembly fabrication (Multicomponent Ink Development, High-Throughput Fabrication, and Scaling Studies node) and cell electrolysis testing (In-Situ Testing Capabilities for Hydrogen Generation node).ANL, together with the LLNL Ab Initio Modeling of Electrochemical Interfaces and LBNL Density Functional Theory and Ab Initio Calculations nodes, investigated the factors that may alter the transport property of a cobalt-based oxygen evolution reaction catalyst, developed by ANL for proton exchange membrane electrolysis. The LLNL team found the origin of the discrepancy between the reported experimental and theory-derived electronic structure of cobalt oxide. This resulted in the confidence to choose a specific theory that can provide reliable information about the electronic structure of the cobalt oxide materials family. This is crucial to reliably identify the factors that determine the transport property of this material, which affects the overall catalytic activity. HydroGEN looks forward to growing its membership of industry, university and laboratory collaborators that can partner with member-laboratory experts by way of CRADAs and potential future FOAs. Moving forward, HydroGEN will expand its presence in the AWS community through working group meetings and participation at relevant professional meetings.

Preliminary Study on In-Situ Test for Testing Operation Error for Shear Wave Velocity at Class III Site

A special in-situ test for shear wave velocity at class III site is conducted in the given borehole by three professional groups using the same suspension logging apparatus. Testing operation error for shear wave velocity and its effect on ground motion with different intensity are investigated. The main conclusions are as follows: (1) the testing operation error for shear wave velocity exists objectively. The testing data in this paper indicate the error is independent on burying depth and the maximum value of error is less than 20%; (2) when the amplitude of input acceleration is not more than 0.2g, the effect for testing operation error on ground motion can be ignored. However, when the input acceleration is larger, this effect becomes larger and should be recognized and examined carefully.

Establishing Relationships between Parameters of the Controlled Compaction Soil by Using Various In-Situ Tests

The aim of research was evaluating reliable correlations between chosen soil parameters describing state of surface layers of soil. The paper presents site comparative tests based on the light falling weight deflectometer (LFWD), the static plate load tester (VSS), the dynamic probing light tester (DPL) and the bearing ratio tester (CBR in-situ) with relationships between soil state parameters. All featured in-situ tests were conducted based on Polish experiences and Standards used in engineering practice.

Combined In-Situ and Laboratory Minor Destructive Testing of Historical Mortars

ABSTRACTMortar is of all masonry components the most difficult to be experimentally characterized in heritage buildings. This article investigates the possibility of combining different in-situ and laboratory minor destructive testing (MDT) techniques to assess the strength of mortar in historical brickwork. Lime mortar and clay brick walls were built in the laboratory and then tested in order to derive empirical correlation rules among three different MDT techniques: double punch test (DPT), helix pull-out test (HPT), and pin penetration test (PPT). The outcomes of this activity were used eventually to assess the mortar properties of an important historical heritage structure, Casa Puig i Cadafalch, located near Barcelona. The research is intended to promote the use of MDT in studies and conservation works on built cultural heritage by providing criteria for the evaluation of the strength of existing mortar with respectful sampling and testing techniques.

FEBEX In-Situ Test: Preliminary Results of the Geochemical Characterization of the Metal/Bentonite Interface

The in situ Full-scale Engineered Barrier Experiment (FEBEX) in Grimsel (Switzerland) has been dismantled after 18 years of operation. The test was designed to demonstrate the feasibility of manufacturing and assembling the engineered barriers and to monitor the performance of a real-scale Engineered Barrier System (EBS) in the long-term. Samples of bentonite in contact with different metallic components were collected during dismantling activities to examine the alteration processes induced in the bentonite by the corrosion of metals. The samples cover different positions of the bentonite barrier to check the effect of saturation and hydration on the geochemical processes observed. This paper presents the results on the soluble ions, exchangeable cations, CEC, adsorbed iron and mineralogy in three samples of bentonite located at the vicinity of the heater and another one near the contact of the bentonite with the granite. According to results obtained, temperature and hydration seems to have a significant effect on the geochemical evolution of the interface and, therefore, in the initialization of corrosion processes. Lack of available water in the surroundings of the heater seems to constrain the Fe-related alteration processes.

In-Situ Test of Pressure Pipeline Vibration based on Data Acquisition and Signal Processing

Abstract Pipeline vibration of high frequency and large amplitude is an important factor that impacts the safe operation of pumping station and the efficiency of the pumps. Through conducting the vibration in-situ test of pipeline system in the pumping station, we can objectively analyze the mechanism of pipeline vibration and evaluate the stability of pipeline operation. By using DASP (data acquisition & signal processing) in the in-situ test on the 2# pipeline of the third pumping station in the general main line of Jingtaichuan electric-lifting irrigation project in Gansu Province (later known as “the general trunk third pumping station in Jingtai electric project”) and then adopting time-domain analysis and cross-spectrum analysis to deal with collected data, we can acquire the vibration state in different positions of pipeline. Tests have shown that, the application of DASP in the vibration test of pressure pipeline of the pumping station, compared to the traditional test systems, can not only obtain higher test accuracy and efficiency, but can also provide theory basis and technical support for solving the vibration problems of the same-type pipeline operation. It has a good promotion value in the engineering practice.

Research of the Shear Strength Test of the Soil on the Surface of Lop Nor Gobi

By Applying the Self-Made Field in-Situ Direct Shear Equipment, it Makes a Series of in-Situ Direct Shear Test Researches on the Soil （＜10cm）on the Surface of the Gravelly Gobi in Lop Nor, Xinjiang, Achieving its Shear Strength Parameter. the Conclusion that this Paper Gets Not only Provides the Key Parameters Needed for the Design of the Gobi Surface Soil Collection Machine and the Relevant Assessment Experiments, but also Offers the Reference for Evaluating the Similar Soil Shear Strength of the Gobi Engineering Construction.