Ultrasonic Pulse Velocity Of Concrete Research Articles

Methodology for Determining the Correct Ultrasonic Pulse Velocity in Concrete

Quite often, concrete strength parameters must be determined in the shortest possible time. Due to the strong correlation between concrete’s mechanical and acoustic properties, ultrasonic devices can be used for this purpose. However, the ultrasonic pulse velocity (UPV) is influenced by a variety of factors, including the curing and exploitation conditions of the concrete, the presence of reinforcement, and other various physical factors. Ignoring these factors may contribute to the misinterpretation of the measurement data when determining the strength of the concrete. Typically, all these factors are analyzed independently. This publication consolidates the findings obtained from our research efforts and field expertise over the past two decades. It outlines the elaborated UPV measurement methodology based on the integration of a four-argument function: the hydration process phase of the hardened cement paste (or concrete aged three days and older), hardening (curing) condition, concrete moisture level, and ambient temperature. To understand the interactions of the key factors, different ultrasonic devices were used to measure the velocities of longitudinal and surface waves in concrete by applying direct and indirect transmission methods when concrete specimens were tested under different moisture and temperature conditions.

Effects of coral aggregate properties on the ultrasonic pulse velocity of concrete

For the non-destructive evaluation of concrete properties and internal damage monitoring, the ultrasonic pulse velocity (UPV) method has been widely employed; however, for coral concrete, crucial characterization parameters such as UPV are still unknown. Thus, this paper focuses on coral concrete UPV characteristics, especially with respect to porosity and compressive strength. The results show that the coral aggregate has diverse morphologies and complex internal structure, which greatly affects the homogeneity of its UPV, which ranges from 2550–3850 m/s, and these are also the main reason for the UPV dispersion effect in coral concrete. Due to the lower UPV of coral coarse aggregate, the UPV of coral mortar was higher than that of coral concrete in the same condition. In addition, the three-dimensional of large-aggregate distribution in coral concrete had a remarkable effect on ultrasonic wave propagation path in coral concrete. It was also found that the coral concrete porosity, compressive strength and UPV are strongly correlated specifically the compressive strength and UPV are linearly positively correlated. The UPV of coral concrete in the dry state is approximately 3950–4450 m/s and its porosity is approximately 14.3 %–21.5 %, and the relationship between the two is more reliably characterized by an exponential function. Furthermore, the linear correlation between coral concrete strength and UPV can be effectively improved by reducing aggregate particle size, thus, the strength can be inferred by the UPV method within a certain range.

Mathematical model for predicting the ultrasonic pulse velocity of concrete

This paper proposes a mathematical model approach to predict the Ultrasonic Pulse Velocity (UPV) of concrete. This paper presents the formulation, calibration, evaluation, and validation of the proposed UPV model. An experimental program was developed to calibrate and evaluate the proposed model. Furthermore, the model was validated using a separate group of measurements in the experimental program, to test its accuracy and generalization capability. Analysis of the results reveals that the proposed model provides a good fit to the experimental data and does not contain outliers or discerning pattern. The corresponding standard error and determination coefficient are 45 m/s and 0.92, respectively. Model validation demonstrates high predictability and generalization capability. The corresponding standard error and determination coefficient are 74 m/s and 0.91, respectively.

Experimental investigation and AI prediction modelling of ceramic waste powder concrete – An approach towards sustainable construction

The ceramic waste powder (CWP) is generated in the ceramic industry during the cutting and polishing stages. It is harmful to the environment and needs a massive area for disposal. Therefore, an alternative way is required to reduce the environmental pollution and landfill caused by CWP. The aim of the study is to establish an Artificial Intelligence (AI) model for CWP concrete from the experimental results to save time and cost. Advancements in AI have made the estimation of concrete mechanical characteristics possible by employing Machine Learning (ML) approaches. In the current study, 60 concrete mixes with waste CWP are made as a partial replacement of cement by 10% and 20%. The plain concrete's ultrasonic pulse velocity (UPV) is taken as a reference. Furthermore, supervised ML techniques (i.e., Bagging, XG Boost, AdaBoost) and standalone (Decision tree) are employed to foresee the UPV of CWP concrete (CWPC). The prediction model's performance is evaluated using R2, Root Mean Square Error (RMSE) values, and Mean Absolute Error (MAE). The k-fold cross-validation is used to validate the performance of the prediction model. The XG Boost model, with an R2 value of 0.95, performed better compared to Bagging, AdaBoost, and DT models. Among all ensemble and individual models, the XG Boost model performs better with higher R2 and lower RMSE (0.081 km/s) and MAE (0.063 km/s) values. Therefore, the CWPC, as a construction material, would reduce land degradation and water pollution. In addition, applying ML techniques for estimating concrete characteristics would have reduced the consumption of efforts, resources, and time of researchers in the construction sector.

The effect of sulfuric acid attack on mechanical properties of steel fiber-reinforced concrete containing waste nylon aggregates: Experiments and RSM-based optimization

Replacing natural aggregate with recycled plastic has been a strategy to reduce pollution associated with conventional concrete production and disposal of plastic materials. Due to the possibility of structures subject to acid attacks, it is of value to check the resistance of concrete against these attacks. The present study evaluates the behavior of concrete containing steel fibers and nylon granules under sulfuric acid attack. 9 batches of concrete containing 0, 10, and 20% (by volume) of nylon granules, replacing natural sand and three volume percentage of steel fibers (0, 0.75, and 1.25%) were prepared. First, concretes were placed in a 5% sulfuric acid solution for 0, 45, and 90 days, and then their ultrasonic pulse velocity (UPV) and compressive capacity were evaluated. The microstructural behavior of concretes was also investigated through scanning electron microscopy (SEM) and energy dispersive X-ray microanalysis (EDXMA). Finally, a model using the response surface method (RSM) was proposed to optimize the content of steel fibers and nylon granules in concrete to achieve the maximum strength of concrete in an acidic environment. The results show that increasing the acid exposure time decreases the compressive capacity and UPV of concrete. Concrete with a higher nylon granule content exhibits a lower strength and UPV decline rate due to acid immersion when compared to that with a lower nylon granule content. After optimization, it was found that the optimal volume percentage of steel fibers and nylon granules in concrete after 90 days of acid exposure is 0.11% and 20% to maximize the compressive strength, respectively. The findings of this study help to minimize the extraction of non-renewable natural resources and the environmental impact of waste nylons by developing cleaner and more sustainable concrete.

Prediction of Compressive Strength of Normal Concrete with Partial Replacement of Sand by Waste Glass Using Fuzzy Model

The objective of the study is a partial replacement of natural fine aggregate with crushed waste glass for M 30 concrete production. To determine the compressive strength of such concrete for using 10% 15%, 20%, and 25% of partial replacement including control samples using 0.45, 0.47, and 0.50 water-cement ratios. Quality tests, slump, compressive strength, density, permeability, and Ultrasonic pulse velocity test are performed; the cube of concrete mix design test follows the American Concrete Institution (ACI) guideline. And to develop a predictive model for the 7days and 28days compressive strength using a fuzzy model. The result has shown that the physical properties, of course, fine aggregate and crushed waste glass satisfy the standard specification, when the replacement percent increases, the compressive strength and ultrasonic pulse velocity of concrete are increased up to 15% of replacement level Due to the angular nature of waste glass particles contributes more effective cement past. Thus reduction of microscopic voids in concrete. The study also found the depth of penetration for concrete indicates the increased replacement percent increase in the depth of penetration increase due to increase microscopic void space. It was concluded that the natural sand is effectively partially replaced by crushed waste glass, maximum compressive strength was achieved at 15% of replacement level. The result showed that quite satisfactory in predicting the Compressive strength for 7 and 28 days strength of the M-30 concrete mix using the fuzzy logic technique with a coefficient of correlation, R2 of 0.87 and 0.85 respectively for training and validation set. The significance of the study is that the compressive strength of concrete made with partial replacement of natural fine aggregate by the crushed waste glass can be predicted by using the predictive model developed.

Investigating the Ultrasonic Pulse Velocity of Concrete Containing Waste Marble Dust and Its Estimation Using Artificial Intelligence.

Researchers and engineers are presently focusing on efficient waste material utilization in the construction sector to reduce waste. Waste marble dust has been added to concrete to minimize pollution and landfills problems. Therefore, marble dust was utilized in concrete, and its prediction was made via an artificial intelligence approach to give an easier way to scholars for sustainable construction. Various blends of concrete having 40 mixes were made as partial substitutes for waste marble dust. The ultrasonic pulse velocity of waste marble dust concrete (WMDC) was compared to a control mix without marble dust. Additionally, this research used standalone (multiple-layer perceptron neural network) and supervised machine learning methods (Bagging, AdaBoost, and Random Forest) to predict the ultrasonic pulse velocity of waste marble dust concrete. The models’ performances were assessed using R2, RMSE, and MAE. Then, the models’ performances were validated using k-fold cross-validation. Furthermore, the effect of raw ingredients and their interactions using SHAP analysis was evaluated. The Random Forest model, with an R2 of 0.98, outperforms the MLPNN, Bagging, and AdaBoost models. Compared to all the other models (individual and ensemble), the Random Forest model with greater R2 and lower error (RMSE, MAE) has a superior performance. SHAP analysis revealed that marble dust content has a positive and direct influence on and relationship to the ultrasonic pulse velocity of concrete. Using machine learning to forecast concrete properties saves time, resources, and effort for scholars in the engineering sector.

Effect of waste sandstone microfines on mechanical strength, abrasion resistance, and permeability properties of concrete

River sand is a non-renewable resource. The erosion of rocks obtains it, taking thousands of years. The mining of river sand is increasing exponentially due to rapid economic growth and urbanization. Due to a shortage of river sand, low-quality river sand is being used in construction. Concrete can be made more resource-efficient and sustainable by using waste and recyclable materials for sand. Nowadays, manufactured sand (M-sand) is being utilized in construction to lessen the natural sand demand. Higher fines content, angular shape of particles, increased surface area, and rough texture are the key characteristics of M-Sand. The prime focus of this research article is to evaluate the potential of sand made from quarry waste of sandstone to be used as a 100 per cent replacement of river sand in concrete. Waste sandstone microfines were also used and replaced with fine aggregate from 5 to 25%, by weight with an increment of 5%. The generation of microfines is an unavoidable part of the sand manufacturing process. Microfines are particles of size less than 75 µm. These microfines are discarded through sieving or washing, resulting in a waste of our valuable and non-renewable natural resources. The effect of the w/c ratio and sandstone microfine content on the workability, mechanical strength, abrasion resistance, permeability, and ultrasonic pulse velocity of concrete is demonstrated in this paper. The tests revealed that M-sand and microfine content significantly influence concrete's fresh and hardened properties. The strong interlocking of M-sand particles and the filler effect caused by microfines improved concrete's mechanical strength and durability parameters. However, this positive impact of microfines in concrete is lowered by the higher entrapped air at a low w/c ratio. This study establishes that using moderate amounts of sandstone microfines in M-sand can be a sustainable approach to solve the problem of natural sand shortage and reduce the loads from landfills.

Recycled Refractory Brick as Aggregate for Eco-friendly Concrete Production

The amount of construction and demolition waste continues to increase year by year.These wastes have a significant harmful influence on the environment; refractory brick is among of these wastes. this paper concerns the reuse of refractory brick wastes to produce an eco-friendly concrete. To achieve this objective,coarse and fine Natural Aggregates (NA) were partially replaced with recycled Refractory Brick Aggregates (RBA). According to the design of experiment, two families of mixes were prepared and tested: the first mixes was made with coarse and fine NA (as reference concrete) and the second mixes made by replacing 20% of coarse and fine NA by coarse and fine RBA. For each of the mentioned families, three cement dosages of 350 kg/m3 , 400 kg/m3 , 450 kg/m3 were investigated. A series of experiments including water porosity, density, Ultrasonic Pulse Velocity (UPV) and compressive strength were assessed. Observed results indicate that the use of coarse and fine RBA had a relatively influence on the water porosity and UPV of concrete. However, the use of coarse and fine RBA produces a slightly decreased the density of concrete (below 2%). Moreover, the use of coarse and fine RBA in concrete improved the compressive strength. Hence, coarse and fine RBA can be successfully used to produce concrete with acceptable properties.

Frost influence on the ultrasonic pulse velocity in concrete at early phases of hydration process

Quite often concrete strength parameters have to be determined at an early age. Due to the strong correlation existing between the mechanical and acoustic properties of concrete, ultrasonic devices can be used for this purpose. However, the ultrasonic pulse velocity (UPV) is affected by many factors, and it makes a great difference whether the concrete is subject to test at the earlier age or at a later time of exploitation. Since the UPV in ice is higher than in water, an increase of the UPV in concrete are to be expected. This paper describes the effect of frost on the UPV in concrete. The studies were carried out with short-term and long-term freezing of concrete specimens at active phases of the hydration. Significant changes in the UPV in concrete, caused by the interaction of frost and moisture, have been established.

Estimating the Concrete Compressive Strength by Using the Concrete Ultrasonic Pulse Velocity and Moduli of Elasticity

Developing a non-destructive method which delivers fast, accurate and non-invasive results regarding the concrete compressive strength, is an important issue, currently investigated by many researchers all over the world. Different methodologies, like using the simple non-destructive testing (NDT) or the fusion of different techniques approach, were taken into consideration in order to find the optimal, most suitable method. The purpose of this paper is to present a new approach in this direction. The methodology consists in predicting the concrete compressive strength through ultrasonic testing, for non-destructive determination of the dynamic and static moduli of elasticity. One important, basic assumption of the proposed methodology considers values provided by technical literature for concrete dynamic Poisson’s coefficient. The air-dry density was experimentally determined on concrete cores. The dynamic modulus of elasticity was also experimentally determined by using the ultrasonic pulse velocity (UPV) method on concrete cores. Further on, the static modulus of elasticity and the concrete compressive strength can be mathematically calculated, by using the previously mentioned parameters. The experimental procedures were performed on concrete specimens, namely concrete cores extracted from the raft foundation of a multistorey building; initially they were subjected to the specific NDT, namely ultrasonic testing, and the validation of the results and the proposed methodology derives from the destructive testing of the specimens. The destructive testing is generally recognized as the most trustable method. The precision of the proposed method, established with respect to the destructive testing, revealed a high level of confidence, exceeding 90% (as mean value). It was noticed that even the cores with compressive strength outside of mean range interval (minimum and maximum values) presented high rate of precision, not influencing the overall result. The high rate of accuracy makes this method a suitable research background for further investigations, in order to establish a reliable NDT methodology which could substitute the very invasive and less convenient, destructive method.

Deep learning model for estimating the mechanical properties of concrete containing silica fume exposed to high temperatures

In this study, the deep learning models for estimating the mechanical properties of concrete containing silica fume subjected to high temperatures were devised. Silica fume was used at concentrations of 0%, 5%, 10%, and 20%. Cube specimens (100 mm × 100 mm × 100 mm) were prepared for testing the compressive strength and ultrasonic pulse velocity. They were cured at 20°C±2°C in a standard cure for 7, 28, and 90 d. After curing, they were subjected to temperatures of 20°C, 200°C, 400°C, 600°C, and 800°C. Two well-known deep learning approaches, i.e., stacked autoencoders and long short-term memory (LSTM) networks, were used for forecasting the compressive strength and ultrasonic pulse velocity of concrete containing silica fume subjected to high temperatures. The forecasting experiments were carried out using MATLAB deep learning and neural network tools, respectively. Various statistical measures were used to validate the prediction performances of both the approaches. This study found that the LSTM network achieved better results than the stacked autoencoders. In addition, this study found that deep learning, which has a very good prediction ability with little experimental data, was a convenient method for civil engineering.

Compressive Strength and Ultrasonic Pulse Velocity of Concrete with Metakaolin

The intention of the present study is to assess the possibility of using Metakaolin as a partial replacement of Portland Pozzolana Cement (PPC) in the concrete to improve its workability and compressive strength. It also explores the study on the connection between ultrasonic pulse velocity (UPV) on different replacement percentage of mineral metakaolin and compressive strength by using a compression testing machine for M40 grade of concrete. Concrete specimens were cast of size 150 mmx150 mm x150mm by partial replacing PPC with metakaolin in the range of 4% to 28 % by the weight of cement. For better consistency and workability the Visco-Flux superplasticizer was used. Usual procedure of water curing of specimens was done for 7, 28, and 90 days to determine the effect of curing time on strength. All 8 different mix specimens were tested for compressive strength and ultrasonic pulse velocity. It was observed that up to 24% metakaolin replacement the strength was increased but after that, the strength gets reduced as compared to the normal concrete and the optimum value of compressive strength was obtained at 16% metakaolin replacement. The increase in the UPV of test samples indicated the formation of the homogeneous structure due to the addition of metakaolin. So the use of metakaolin as a partial replacement of PPC in concrete is a good choice to reduce the cost of production and increase the strength of concrete. A mathematical model is generated by regression analysis in the form of an equation to correlate the compressive strength and ultrasonic pulse velocity.

The influence of steel reinforcement on ultrasonic pulse velocity measurements in concrete of different strength ranges

The present paper reports on the assessment of concrete strength, using non-destructive testing devices. The study focuses on Ultrasonic Pulse Velocity (UPV) as a non-destructive tool for estimating the compressive strength of the concrete in real structures, using a UPV-strength correlation model. The objective is to highlight the steel reinforcement influence on the ultrasound pulse velocity (UPV) measurement as a mean of a non-destructive strength assessment of the concrete. UPV-strength correlation models are built on the basis of laboratory plain concrete specimens tested to destruction. However, the real life structures contain steel reinforcement which interferes with UPV measurements, resulting in the distortion of these measurements, particularly when the reinforcement bars lie in the wave propagation path. Thus, when assessing the quality of the concrete in real structures, it is recommended to avoid reinforcement rebars, which is often difficult, if not impossible to ensure, especially for highly reinforced structural elements. This work proposes an alternative which consists of assessing the influence of steel reinforcement on UPV measurements through a correction factor for UPV readings that will allow the user to take account of the presence of steel reinforcement when assessing the concrete strength of real structures through an ultra-sound pulse velocity testing. In the study, concretes in three different strength ranges were targeted; the aim being to assess the role of the concrete density and the manner with which it interacts with reinforcement rebars when measuring UPV in reinforced concrete structures. The strength ranges considered vary from ordinary, to moderate, to the high strength concrete. Cylindrical moulds made of concrete from three different strength ranges were cast; some of these moulds were reinforced with different longitudinal steel ratios (low, moderate, high) to simulate real practical cases. These concrete moulds were then subjected to UPV tests in the parallel and perpendicular directions to the rebars disposition in order to study the reinforcement influence on UPV from the two directions. A correction factor was then developed to work out of the real ultrasonic pulse velocity of concrete that can be used in the UPV-strength correlation model to determine the compressive strength. For the three concrete strength ranges considered in this study, the presence of steel reinforcement was found to affect the UPV measurements. The results show also that the effect of steel rebar on UPV measurements is more accentuated with a low concrete density, particularly in the presence of a high steel ratio and rebar lying in the parallel direction to the wave propagation path. Indeed, for high performances concrete, which is a higher density concrete, a high steel ratio was found to slightly modify the pulse velocity; moderate and low steel ratios did not affect the pulse velocity. For moderate and normal strength concretes, however, high and moderate steel ratios had noticeable effects on the UPV measurements, especially in the parallel direction; showing that UPV testing is not only affected by the presence of steel reinforcement in concrete, but it is also related to the steel ratio, the rebar disposition, and the concrete density. A correction factor is then necessary for UPV measurements to correlate the strengths of reinforced concrete structures.

Nanosilica-added concrete: strength and its correlation with time-dependent properties

This paper presents results of an experimental investigation on fresh and hardened properties of high-performance concrete (HPC) containing nanosilica (nS), and a comparison with HPC containing microsilica (mS), and a reference concrete (RefCon). The temperature of fresh concrete was monitored using maturity sensors. The compressive strength, splitting-tensile strength, flexural strength, elastic modulus, rebound hammer number and ultrasonic pulse velocity of concrete were determined at different ages, and correlated with creep and drying shrinkage results reported earlier by the authors. The study revealed that nS has accelerated the strength development at early ages, whereas the mS addition showed no significant change. The nS-HPC exhibited improved mechanical properties as compared to the other concretes. The correlation between compressive strength and maturity, as obtained, would be useful for carrying out early-age construction activities. A good correspondence was also noted between the mechanical properties obtained from destructive and non-destructive testing. The correlation of mechanical properties and time-dependent properties revealed that, in spite of improvement in the former, the nS-HPC exhibited higher creep and drying shrinkage than other two concretes. As a result, suitable suggestions are made to account for this in the design of structural elements.

Influence of silica fume and blast furnace slag on the dynamic and mechanical properties of concrete

The present paper focuses on the impact of additives, such as silica fume (SF) and blast furnace slag on the mechanical properties of ordinary concrete. Moreover, the modulus of elasticity, ultrasonic pulse velocity, compressive strength, and porosity are assessed with the objective of quantifying the consequences of the different additives. The dynamic modulus of elasticity and ultrasonic pulse velocity of concrete are remarkably affected by age, as indicated by the results obtained. In additive, the incorporation of additives has a significant impact on the dynamic modulus of elasticity, the ultrasonic pulse velocity and the compressive strength. Concretes including additives have a larger dynamic modulus of elasticity and higher ultrasonic pulse velocity; Concretes with silica fume have significantly higher strengths than those of ordinary concretes and concretes containing blast furnace slag. Good correlations are observed between the dynamic modulus of elasticity and the compressive strength, between the ultrasonic pulse velocity and dynamic modulus of elasticity, between the ultrasonic pulse velocity and compressive strength.

Water content and temperature effect on ultrasonic pulse velocity of concrete

In this paper, water content and temperature effect on the ultrasonic pulse velocity (UPV) of concrete was investigated. A series of tests were performed to examine the relationship between water content and UPV of concrete with different aggregate mixture proportions. Cube test specimens were made of concrete with water-cement ratio of 0.5. The concrete specimens were immersed in water for 90 days to saturate them. To measure the effect of different water contents on UPV, the test specimens were dried gradually to change the amount of water between measurements. This process was repeated until the concrete pieces was completely dried and weight no longer changed. The water content could be changed from about 6 to 0%. Following, another test procedure was conducted to research the relationship between temperature and UPV. To measure the influence of various temperature on UPV, completely dried concrete specimens were firstly cooled to –18°C and gradually heated to +180°C. In these two different procedures, the UPV values corresponding water content and temperature in the relevant ranges were periodically measured. The test results indicate that the increase in both water content and temperature increases almost linearly UPV of concrete. Based on correlation derived from the test data, irrespective of concrete properties a further increase in both water content of 1% and temperature of 10°C increases UPV of average 160 and 34 m/s, respectively. As overall assessment, this study demonstrates that the UPV is a function of both water content and temperature, and the changing of these two parameters has an important influence on ultrasonic pulse velocity of concrete.

Effect of types of aggregate and sand-to-aggregate volume ratio on UPV in concrete

An experimental investigation was carried out to understand the variation of ultrasonic pulse velocity (UPV) in concrete with the types of coarse aggregate and sand-to-aggregate volume ratio (s/a). The types of aggregate investigated were brick chips, crushed stone, round shaped stone and black stone. Sand-to-aggregate ratios were 0.36, 0.40, and 0.44 and W/C ratios were 0.45, 0.50, and 0.55. Concrete specimens were made and tested for UPV, compressive strength, and modulus of elasticity. UPV in concrete is significantly influenced by the types of aggregate and s/a ratio in addition to the compressive strength of concrete. UPV in concrete is reduced with the increase of s/a ratio. Relationships between UPV and compressive strength, and UPV and modulus of elasticity are proposed for aggregates investigated.

Effect of Coupling Media on Ultrasonic Pulse Velocity in Concrete: A Preliminary Investigation

Effect of Coupling Media on Ultrasonic Pulse Velocity in Concrete: A Preliminary Investigation

Effect of cooling regime on the residual performance of high-volume palm oil fuel ash concrete exposed to high temperatures

This paper presents the experimental findings of a study on the effect of cooling method on the residual performance of concrete containing a high volume of palm oil fuel ash (POFA) exposed to high temperatures. In this study, concrete samples were made in which the ordinary Portland cement was replaced by 50%, 60% and 70% POFA. The test specimens were then thermally treated to elevated temperatures of 200, 400, 600 and 800°C in an electric furnace for a period of 1h. The specimens were cured by air cooling or water cooling and examined for ultrasonic pulse velocity and changes in weight and residual compressive strength. At higher temperatures, the reduction in the ultrasonic pulse velocity of concrete was higher for all of the mixes. Along with the loss of weight, the residual compressive strength of concrete was also reduced. Of the two regimes, the air-cooling system exhibited better performance in recovering the structural properties of concrete containing a high volume of POFA.