Concrete Chloride Research Articles

Experimental study on chloride ion diffusion behavior and microstructure in concrete under alternating ambient humidity conditions

The migration of chloride in concrete in atmospheric zones is mainly influenced by climatic conditions, e.g., various dry-wet cycles in marine tidal zones, and ambient humidity is one of the most important influences. Ambient humidity also determines the moisture content in concrete, which is necessary for the diffusion or transport of chloride in concrete and can enhance the migration of chloride in micropores, thus affecting the distribution of chloride in concrete. In this study, the effects of chloride diffusion and its mechanism, and the evolution of moisture in concrete under alternating drying-wetting cycles, were investigated using an environmental moisture simulation chamber. Chloride diffusion tests were also performed to evaluate the effects of different dry-wet ratios and numbers of drying-wetting cycles on the chloride diffusion depth, chloride content and saturation in concrete. The microstructure of concrete was studied and analyzed using XRD, SEM and MIP technology. The findings showed that the saturation of concrete decreased rapidly with increasing number of wet-dry cycles and finally stabilized. Under different alternating moisture conditions, the saturation of concrete was greater, especially when the wetting time was longer. Additionally, in areas near the surface of concrete (depths of 2 mm-6 mm), the chloride content was proportional to the number of wet-dry cycles. In the interior of concrete (depth > 6 mm), when the number of drying-wetting cycles was larger, the chloride concentration was smaller. However, as the number of wet-dry cycles increased, this led to the decalcification of C-S-H gels, which resulted in the reduction in the number of C-S-H reticular gels with good crystallinity. A pore analysis showed that the cumulative pore size and the maximum probability pore size of concrete gradually increased with increasing number of wet-dry cycles, the deterioration of pore structure was more obvious, and the compactness of concrete gradually decreased, which accelerated the migration of chloride in the matrix. Overall, this study can provide reliable and valuable test data for the development and design of high-performance concrete for applications in atmospheric marine tidal zones.

Effectiveness of various types of coating materials applied in reinforced concrete exposed to freeze–thaw cycles and chlorides

This study assesses the durability of coated and uncoated concrete surfaces protected with four different coating materials: water-soluble (BW), solvent-based (BR), mineral (MI), and epoxy (EP). The durability assessment includes evaluating the absorption rate of water, pull-off adhesion strength, and coating material thickness. Concrete samples were subjected to immersion in regular water and a 7% urea solution, followed by cyclic freezing and thawing. Furthermore, the diffusion of chloride ions in concrete was evaluated using the impressed voltage method, with the samples exposed to the aging process immersed in a 3.5% NaCl solution. The results indicate that EP and BW coatings were significantly affected by the presence of urea and freeze–thaw cycles, resulting in a 43% and 47% reduction in pull-off adhesion strength, respectively. Notably, the MI-coated concrete samples exposed to urea solution and the freeze–thaw cycles exhibited a significant reduction in the absorption rate due to the accumulation of crystals on the coating surface, resulting in reduced porosity of the material.

Chloride penetration in concrete with trilinear binding isotherm

Chloride binding in concrete is an important factor and it can significantly affect the penetration speed of chlorides in concrete and thus the service life of concrete structures. In this paper a new chloride binding isotherm is proposed to be included in the diffusion model of chlorides in concrete. Instead of the use of the traditional Freundlich or Langmuir isotherm, the present chloride binding model uses a trilinear function to describe the chloride binding in concrete. The trilinear binding isotherm not only reflects the nonlinear binding feature of chlorides in concrete when it is exposed to a chloride environment, but also makes it possible to achieve an analytical solution of the chloride diffusion equation. In the present paper, the superior of using trilinear binding isotherm to other binding isotherms is demonstrated. The detailed derivation of the analytical solution of the chloride diffusion equation with nonlinear binding feature is described and illustrated. To demonstrate the rationality and accuracy of the analytical solution derived, comparisons between the analytical solution and the numerical solution and experimental results are also provided. It is shown that the chloride diffusion profiles obtained from the chloride diffusion equation with the trilinear binding isotherm are much closer the experimental results than that obtained from the chloride diffusion equation with linear or bilinear binding isotherm.

Pre-treated corn straw fiber for fiber-reinforced concrete preparation with high resistance to chloride ions corrosion

Chloride ions erosion is a negative factor for concrete sustainable usage. Fiber addition is a potential solution, which promotes a tight concrete structure formation resulting in the resistance of chloride ions. Corn straw is a kind of crop waste widely sourced that can be used as sustainable concrete reinforcement material. The traditional recycling method of corn straw including burnt as straw ash is not environment friendly. This work aims to pre-treat corn straw fiber (CSF) by some convenient methods (untreated, water-treated, alkali-treated) and add treated CSFs directly into concrete to prepare fiber-reinforced concrete with excellent mechanical properties and high resistance ability to chloride ions. The component content of different treated CSFs was tested to study the fibers composition and microstructure changes. The heat of hydration, compressive strength, and flexural strength were tested to study the hydration degree and the effect of different treated CSFs on the concrete mechanical performance. The rapid chloride permeability (RCPT) and chloride migration (RCM) tests were designed to study the reinforced concretes chloride ions resistance ability change. In addition, to further explore the mechanism of mechanical performance and chloride ions resistance ability change, water absorption rate (WAR) and mercury intrusion porosity (MIP) were tested to provide more supporting information from the micro-level. It is concluded that CSF treated by Na2SiO3 has the least impurities and a rougher surface with a larger specific surface area bonding with the cement substrate. Compared to the original concrete, the compressive strength of CSF concrete, WT-CSF concrete, and NT-CSF concrete increased by 15.7 %, 17.8 %, and 33.4 % respectively. The results of RCM and RCPT show a decreasing trend with different treated CSFs addition, the NT-CSF concrete shows the greatest decrease with 20.1 %, and 17.5 %, respectively. Except for the rougher surface and less impurities of CSF, the improvement of mechanical performance and chloride ions resistance ability is mainly due to treated CSF, especially the NT-CSF contributes to a denser structure formation based on the MIP and WAR test results. The viscosity of Na2SiO3 solution acts as a binder that helps to tighten the bonding between substrate and CSF. The water adsorbed by CSF and the alkaline environment provided by Na2SiO3 facilitates hydration decreasing the chloride ions migration. At the same time, the cellulose in CSF containing many hydroxyl and carboxyl groups further contributes to the concrete chloride ion resistance improvement due to its weak conductivity and the binding force of ions exchange.

Modeling Electrochemical Performance of Reinforced Concrete in Natural Marine Airborne-Exposure Environments: DURACON Project,10-Year Evaluation

This research evaluation consisted of a detailed statistical analysis of the recorded data in 72 reinforced concrete specimens, from 12 natural test sites (in nine countries) located in chloride-laden environments (marine airborne-exposure test sites located between 50 m and 250 m from seashore), during a natural exposure period of 10 y. The parameters evaluated included the concrete physical-mechanical characteristics; meteorochemical information; natural reinforcing steel’s instantaneous corrosion current density (icorr) and cumulative icorr; and concrete chloride concentration; surface crack width and rebar cross-section loss correlations. This statistical analysis resulted in empirical instantaneous icorr predictions as a function of the exposure microclimates, through linear multiple regressions. These models showed a high linear dependence of the cumulative icorr with the concrete capillary absorption as well as with the meteorochemical parameters. Results obtained in this investigation showed higher corrosion aggressiveness in tropical environments when compared to nontropical ones. The cumulative icorr proved to be an effective tool to indicate the corrosive likelihood and differentiate the stages of Tuutti’s service life model.

Mechanical Performance and Chloride Penetration of Calcium Sulfoaluminate Concrete in Marine Tidal Zone

The enhancement of the durability of sulfoaluminate cement (CSA) in marine environments is of great importance. To this end, an investigation was carried out involving the placement of CSA concrete in the tidal zone of Zhairuoshan Island, Zhoushan, China, and subjected to a 20-month marine tidal exposure test. The comparison was made with ordinary Portland cement (OPC) concrete to evaluate the effectiveness of the former. The test findings indicate that the compressive strength of both types of concrete is reduced by seawater dry-wet cycling, and the porosity of the surface concrete is increased. However, the compressive strength of CSA concrete is observed to be more stable under long-term drying-wetting cycles. When the ettringite in the CSA surface concrete is decomposed due to carbonization and alkalinity reduction, its products will react with Ca2+ and SO42- in seawater to regenerate ettringite to fill in the concrete pores, making the concrete strength more stable and hindering chlorine penetration. Furthermore, CSA concrete exhibits a higher capillary absorption capacity than OPC concrete, which results in chloride accumulation on its surface. However, the diffusion capacity of chloride in CSA concrete is significantly lower than that in OPC concrete.

Surface application of multifunctional compound to prevent and control combined chloride and carbonation corrosion in concrete

This paper presents the performance of a multifunctional generic compound, 4-Aminobenzoic acid (4ABA) as migratory inhibitor applied on hardened concrete surface to curb corrosion due to combined chloride and carbonated environment. Electrochemical techniques (LPR and EIS), gravimetric analysis were applied to evaluate the corrosion performance and the inhibition mechanism of 4ABA. Chloride and carbonation profiles were developed to investigate the dominant cause of corrosion during the exposure. Visual and microscopic analysis of concrete surface and rebar surface was also done. Compressive strength test was performed to study the effect of corrosion inhibitor on strength property of hardened concrete. Results confirm that 4ABA prolonged the passive state of rebar when used as preventive measure and restrained the on-going corrosion process when employed as repair strategy. Combined exposure by chlorides and CO2 leads to redistribution of chloride ions in concrete matrix. The results also conclude that during the combined exposure, chloride ions initiate the corrosion process and carbonation aggravates this process. Application of 4ABA does not influence the strength properties of concrete. ABA has performed the inhibition by protective layer development and shield formation against the negatively charged corrosive ions. Blended cement concrete system which was observed to be more vulnerable to corrosion was seen to attain similar corrosion resistance as OPC concrete after inhibitor application.

Exploring Exact Effects of Various Factors on Chloride Diffusion in Cracked Concrete: ABAQUS-Based Mesoscale Simulations

Chloride ion attack is a major cause of concrete durability problems, and existing studies have rarely addressed the effects of damage zones. In this paper, an improved mesoscale model including five phases was constructed using the finite element software ABAQUS to study the diffusivity of chloride ions in cracked concrete. It was found that the damage zone is negligible when the crack width is less than 50 μm, while the width and depth of the damage zone are about 15 times the crack width and 15% of the crack depth when the crack is greater than 50 μm. The results show that the diffusion of chloride is greatly influenced by the crack width, while it is little-influenced by the crack shape. Low water-cement ratio and adequate hydration of the concrete are also key factors affecting chloride diffusion. In contrast, regular rounded aggregates have a positive effect on reducing chloride diffusion compared to irregularly shaped aggregates, and this effect becomes weaker with increasing service time. In addition, the protective layer can effectively prevent the diffusion of chloride in concrete. Therefore, when designing marine concrete, efforts should be made to ensure that the concrete has a low water-cement ratio, adequate hydration, less cracking and a protective layer.

Decoupling free chloride and water ingress in concrete by a dielectric resonant sensor

The origin of rebars corrosion in concrete infrastructures is frequently associated with the ingress of chloride ions present in water. This is particularly the case of infrastructures located in marine environments or exposed to deicing salts. The present study aims at developing a radio-frequency dielectric sensor dedicated to free chloride ingress monitoring in a well-defined volume of the material. A resonant method operating in a wide frequency range is selected to separate the effects associated with the variation of the real part of the dielectric permittivity and tangent loss. As it will be shown, the method provides useful information on the presence of free chloride in concrete and can be used for the monitoring of chloride diffusion. For this purpose, considering the variation of the transmission parameter S12 value presents clearly some advantages with respect to the frequency shifts of resonances. This allows to decouple water and chloride content.

Chloride desorption mechanisms of cement pastes containing fly ash

The chemical and physical bonds between cement hydrates and chlorides in concrete can immobilize ingressed chlorides and slow free chloride transport in the concrete pore solution. However, the disassociation of bound chlorides due to reduced pH is an unfavorable mechanism because it increases the concentration of free chlorides and the risk of corrosion in reinforced concrete structures. This study investigated the binding and desorption of chlorides in ordinary portland cement (OPC) and blended paste samples containing 15 % and 30 % fly ash. Paste samples were exposed to various concentrations of NaCl, CaCl2, and MgCl2 solutions to assess their chloride binding capacities. Subsequently, they were exposed to various volumes of 1 M nitric acid to study the influence of the pH of the exposure solution on chloride desorption. The results showed that incorporating 15 % and 30 % fly ash increased the chloride binding capacity of the paste samples by 1.76 and 2.16 times compared to OPC. The disassociation of bound chlorides was influenced by the fly ash replacement level, salt cation, and pH of the exposure solution. Increased fly ash replacement levels inhibited chloride desorption and led to the retention of more bound chlorides when the pH decreased.

CHLORIDE CORROSION OF REINFORCING STEEL

Introduction. Many years of experience in examining corrosion conditions show the dangerous adverse effects of chloride media on reinforced concrete structures.Although a large number of domestic and foreign publications have been devoted to the aggressive action of chloride salts on reinforcing steel, protection against chloride corrosion remains a relevant issue.Aim. In this work, the state of this problem, along with the methods for determining the chloride content in concrete, was assessed in order to propose the means to increase its protective action in aggressive chloride media.Materials and methods. This article discusses the following issues:– maximum permissible chloride content in concrete;– binding of chlorides by components in the matrix, the role of the mineral composition of cement;– critical evaluation of methods for determining the chloride content in concrete;– reduction of the diffusion permeability of chlorides in concrete as a method of corrosion protection.Results. The article presents the data on moisture tests of reinforced concrete prepared using Portland cement having various contents of alite, belite, and tricalcium aluminate, as well as CaCl2 additive.Indicated were the challenges of identifying aggressive free chlorides in the matrix. The need to develop a standard method for determining free chlorides in concrete was discussed. Until such a standard is developed, the chloride aggressiveness to steel in concrete can be assessed by the electrochemical method. It was shown that concretes of extremely low diffusion permeability obtained using advanced complex additives that reduce the water demand of concrete mixtures and change the charge of the matrix surface can be used as a protection measure against chloride corrosion.Presented are the results of determining the potentials of steel in concrete by electrochemical method, chlorides in concrete by colorimetric method, and diffusion permeability of chlorides in concrete.Conclusion. The corrosion activity of chlorides against reinforcing steel depends on a large number of factors, including the total chloride content and the amount of free, physically, and chemically bound chlorides.Since chloride binding depends on a large number of technological factors, it is recommended to perform electrochemical tests of reinforcing steel in concrete as per GOST 31383 to assess the hazard level of chlorides introduced into concrete with initial materials; a decision on the protective measures for reinforcing steel in chloride environments should be made on the basis of the obtained results.

Comparison of Standardized Methods for Determining the Diffusion Coefficient of Chloride in Concrete with Thermodynamic Model of Migration

This research paper is the result of observations made during tests according to various standards carried out on behalf of industry. The article presents diffusion coefficient values calculated according to the thermodynamic migration model for twenty different concrete mixes and some selected mixes of the codified approaches known as ASTM 1202, NT BUILD 443, NT BUILD 492, ASTM 1556. The method used here, according to the thermodynamic model of migration, allows determination of the value of the diffusion coefficient after short studies of the migration of chloride ions into concrete and was described in earlier works by one of the authors. Unfortunately, when using standard methods, the values of diffusion coefficients differ significantly from each other. In each concrete, diffusion tests were carried out in the conditions of long-term natural diffusion to verify the values determined by standard methods and according to the thermodynamic model of migration. The analysis conducted for this research paper reveals that the chloride permeability test method according to the standard ASTM C1202-97 has an almost 2.8-fold greater dispersion of the obtained results compared to the thermodynamic model of migration. It was observed that the standard NT BUILD 492 has a 3.8-fold dispersion of results compared to the method with the thermodynamic model of migration. The most time-consuming method is the standard method NT BUILD 443. The largest 3.5-fold dispersion of values concerning the reference value are observed in that method. Moreover, a method based on a thermodynamic migration model seems to be the best option of all analyzed methods. It is a quite quick, but laborious, method that should be tested for a larger number of concrete mixes. A great advantage of this method is that it is promising for a wide range of concrete mixtures, both plain concrete and concrete with various additives and admixtures, as well as high-performance concrete.

Chloride Resistance of Concrete under Complex Stress and Environment

The presence of stress is shown to have a significant impact on chloride ions in concrete. Reinforced concrete is usually durable and cost-effective which has resulted in its widespread use for construction, however, the concrete subjected to environment and load has become increasingly apparently that attacked by aggressive agents such as chloride ion. In this study, the coupling influences are stress effects and environmental problems on the coastline concrete durability have been investigated. A series of cyclic of a wet-dry cycle and submersion tests were performed onto the stressed concrete to obtain an understanding of the physical mechanisms causing the accumulation of chlorides in the interior pores of concrete under different stress types and exposure environments, based on the same duration. Specimens were prepared and subjected to NaCl solution in a wet-dry cycle and submersion, the chloride in the tension zone is gradual with increasing the stress level, as well as the chloride ion in the wet-dry cycle, is increasing the number of cycles. The apparent diffusion coefficient of each specimen was calculated respectively, the profile of concentration at a different section of tension and compression zones were presented in influence factors of the number of cycles, the length of drying phase, and periodic wetting cycles with sodium solution was discussed. After employed Fick’s second law, the results suggested Da in a wet-dry cycle is much higher than the Da in submersion zones.

Probabilistic study of strength and cover effects on reinforced concrete chloride corrosion

Probabilistic study of strength and cover effects on reinforced concrete chloride corrosion

Numerical analysis on corrosion and mechanical performance of shear stud connector in concrete

Geometric shape of shear stud connector plays an important role on its connecting capacity in steel-composite structures. Recent application of steel–concrete structures showed the degradation of structural performance due to aggressive medium from environment. Available research indicated that the presence of chloride ions in concrete induced depassivation on the surface of steel shear stud connector and resulted in its corrosion accordingly. Thus, it is essential to obtain the corroded shape of shear stud connector for further accurate assessing structural performance of steel–concrete composite structure. As the focus of this paper, based on Fick's second law and Butler-Volmer equation, a quantitative simulation method for reaction of corrosion in steel–concrete composite structures was introduced and discussed. Wherein, two steps of this approach were listed. Firstly, mass transportations of chloride ion, oxygen and hydroxide were simulated for their concentration for preparation of electrochemical reaction. Secondly, electrochemical reaction of Ferrum with presence of oxygen and water, catalyzed by chloride ion, was numerically simulated. Furthermore, two cases of ingression of chloride ion into concrete were discussed for the influence of boundary condition on structural characteristics of steel–concrete composite structure. Random distribution of aggregate in concrete was considered. Result of numerical simulation indicated that, corrode shape of shear stud connector was related to configuration of boundary condition and different pull-out performance were obtained by finite element analysis. Moreover, degradation of mechanical properties of shear stud during its service life were provided.

Study on the Relationship between Chloride Ion Penetration and Resistivity of NAC-Cement Concrete

To explore the effect of nano-attapulgite clay (NAC) on the durability of concrete, two kinds of NAC (calcined raw ore and calcined high viscosity ore: calcination at 650 °C for 2 h) were used to study their effects on the durability of concrete, mainly discussing the changes of chloride ion permeability and the resistivity of concrete with NAC. The effect of NAC on the strength of concrete was analyzed by testing the compressive strength of concrete. The two-electrode method, four-electrode method, and concrete resistivity tester were used to analyze the relationship between the testing method and concrete resistivity, and the effect of NAC on concrete resistivity was analyzed. The influence of NAC on the chloride corrosion resistance of concrete was analyzed by measuring the chloride diffusion coefficient, and the relationship between the chloride diffusion coefficient and resistivity was established. The diffusion process of chloride ions in concrete was analyzed by theoretical derivation and numerical simulation. The results show that: calcining raw ore NAC can improve the compressive strength of concrete, while calcining high-viscosity ore reduces the compressive strength of concrete. At the age of 28 days, the strength of concrete mixed with calcined raw ore is about 7.10% higher than that of ordinary concrete, while the compressive strength of concrete mixed with calcined high-viscosity ore is about 4.32% lower than that of common concrete. The resistivity of concrete mixed with calcined raw ore increases the fastest, and the 56 days age is about 15.8% and 29.6% higher than that of ordinary concrete and calcined high-viscosity ore. There is a good negative correlation between concrete resistivity and chloride diffusion coefficient. At 28 days, the incorporation of calcined raw ore concrete decreased by about 19.9% and 49.4% compared with ordinary concrete and calcined high-viscosity ore, respectively. After 10 years of decline, the chloride ion content is 11.1% and 23.2% lower than that of ordinary concrete and concrete mixed with calcined high viscosity ore.

CHARACTERIZATION OF CHLORIDE IONS DIFFUSION IN CONCRETE USING FRACTIONAL BROWNIAN MOTION RUN WITH POWER LAW CLOCK

In this paper, we propose a revised fractional Brownian motion run with a nonlinear clock (fBm-nlc) model and utilize it to illustrate the microscopic mechanism analysis of the fractal derivative diffusion model with variable coefficient (VC-FDM). The power-law mean squared displacement (MSD) links the fBm-nlc model and the VC-FDM via the two-parameter power law clock and the Hurst exponent is 0.5. The MSD is verified by using the experimental points of the chloride ions diffusion in concrete. When compared to the linear Brownian motion, the results show that the power law MSD of the fBm-nlc is much better in fitting the experimental points of chloride ions in concrete. The fBm-nlc clearly interprets the VC-FDM and provides a microscopic strategy in characterizing different types of non-Fickian diffusion processes with more different nonlinear functions.

Prediction of the durability of high-performance concrete using an integrated RF-LSSVM model

In extremely cold and complex marine environments, strong concrete chloride ion penetration resistance is the key to ensuring the durability of buildings (structures). Quickly and accurately predicting the resistance of concrete to chloride penetration is critical to optimizing the concrete mix proportions. A hybrid intelligent prediction model that integrates random forest (RF) and least squares support vector machine (LSSVM) algorithms is proposed to rapidly and accurately predict the resistance of high-performance concrete (HPC) to chloride penetration. The initial index system of HPC chloride penetration resistance was established from substantial research and practical projects. An RF is employed to screen the initial index parameters and to provide an optimal index set for predicting concrete resistance to chloride penetration. Based on a sample data set, the LSSVM is implemented to establish high-precision predictions regarding the resistance of concrete to chloride penetration. The results indicate that (1) the RF method effectively screens important indicators and provides the optimal data set for the prediction of concrete resistance to chloride penetration and (2) the developed RF-LSSVM hybrid intelligent approach can effectively and accurately predict the resistance of concrete to chloride penetration. For the test set, the RMSE and R2 of the prediction model reach 0.0491 and 0.941, respectively, representing accuracy better than that typical for machine learning algorithms. The proposed RF-LSSVM hybrid intelligence model can provide a basis for optimizing the concrete mix proportion and can be applied in practical projects to help solve similar problems.

Diffusion resisting performance of concrete modified with sodium methyl silicate in saline soil area

• A new type of concrete mixed 2.4% sodium methyl silicate was prepared. • An instantaneous diffusion model of chloride ions in concrete was proposed. • The diffusion reducing performance of the new concrete were compared against ordinary concrete. • A useful means for the corrosion resistance of tunnel lining was proposed. Concrete of tunnel lining in saline soil area is subjected to compound salt attacks, which decrease the service life of tunnel. In this study, a new type of concrete mixed 2.4 % sodium methyl silicate was prepared to improve the compound salt damage resistance of concrete. The properties of the concrete, including chloride diffusion resisting performance, compressive strength, and water absorption, were investigated. The results showed that the chloride diffusion resisting performance of the concrete modified with methyl sodium silicate was notably better than that of normal concrete in compound salt solution. The maximum compressive strength had not changed significantly compared with normal concrete, while the occurrence of peak strength was delayed by about 30 days. The water absorption of the concrete modified with sodium methyl silicate was reduced by 21.09 % compared with the normal concrete. Moreover, chloride diffusion resisting mechanism of the concrete immersed in compound salt solution was elucidated. Furthermore, based on the Fick’s second law and experimental results, a time-varying diffusion model for predicting the chloride ion mass fraction of chloride in the concrete was proposed in this paper. The proposed approach is a useful means for the chloride diffusion resisting of concrete in some saline soil area of Western China.

A machine learning method for predicting the chloride migration coefficient of concrete

• Extensive model optimizations and performance evaluations are carried out. • XGBoost predicts the chloride migration coefficient with the highest accuracy. • XGBoost outperforms other five tree-based algorithms. • Fresh density and strength tests are predictors of the chloride migration coefficient. • The models can replace traditional laboratory-based concrete chloride migration tests. This work adopts a state-of-the-art machine learning algorithm, XGBoost, to predict the chloride migration coefficient (D nssm ) of concrete. An extensive database of experimental data covering various concrete types is created by gathering from research projects and previously published studies. A total of four D nssm models are developed depending on the number and type of input features. All models are verified with unseen data using four statistical performance indicators and compared to other five tree-based algorithms. The verification results confirm that the XGBoost model predicts the D nssm with high accuracy. The model has the potential to replace cumbersome, time-consuming and resource-intensive laboratory testing.