Sea-sand Concrete Research Articles

Experimental Study on Bond Fatigue Between Carbon Fiber-Reinforced Polymer Bars and Seawater–Sea Sand Concrete Under Seawater Immersion and Dry–Wet Cycle Conditions

The durability of carbon fiber-reinforced polymer (CFRP) bars in marine environments is essential for their application in seawater–sea sand concrete (SWSSC), especially under cyclic loading conditions. While previous studies primarily focused on static bonding performance, the effects of seawater immersion and dry–wet cycles on bond fatigue behavior at CFRP–SWSSC interfaces remain underexplored. This study investigated the bond fatigue performance of CFRP bars and SWSSC under seawater immersion and dry–wet cycling conditions. Eighteen CFRP bar-SWSSC bond specimens were divided into three categories and prepared for static and fatigue pull-out tests. The effects of varying stress levels (fatigue upper load/static bond ultimate load) after seawater immersion and dry–wet cycling on fatigue failure modes, bond–slip behavior, and fatigue characteristics were evaluated. The results show that seawater immersion and dry–wet cycling significantly degrade the performance of bonds between CFRP bars and SWSSC, with an average bond strength reduction of 10.31%. These conditions reduce fatigue cycles and stiffness while increasing bond–slip (relative displacement at the bar–concrete interface) and residual–slip (displacement after unloading). Moreover, dry–wet cycling has a greater negative impact on fatigue bond performance than seawater immersion. Higher fatigue stress levels exacerbate damage and crack propagation at the CFRP–SWSSC interface, leading to significant increases in both bond–slip and residual-slip. Under similar conditions, higher stress levels enhance bond stiffness. However, excessively high stresses may lead to bond fatigue failures. Using experimental data and existing fatigue bond–slip constitutive models, a customized model for CFRP bars in SWSSC was developed. These findings highlight that marine environments and fatigue loading severely impair bond performance, thereby emphasizing the importance of careful design for marine applications. The proposed model offers a reliable framework for predicting bond–slip behavior under fatigue conditions, enhancing the understanding of CFRP–SWSSC interactions and supporting the design of durable marine infrastructure.

Mechanical properties and flexural toughness evaluation method of mono/hybrid fiber-reinforced ultra-high performance seawater sea sand concrete

Mechanical properties and flexural toughness evaluation method of mono/hybrid fiber-reinforced ultra-high performance seawater sea sand concrete

Multi-scale investigation of stainless-steel passivation in seawater concrete pore solution

Stainless-steel bars can be effectively used in seawater sea sand concrete due to their excellent resistance to chloride ions, contributing to resource conservation and sustainable development. However, the underlying impact mechanism of chloride ion on the passivation of stainless steel in seawater sea sand concrete has not been thoroughly studied. In this work, a multi-scale study was carried out to reveal the role of chloride ion on the passivation of stainless-steel bar in concrete. At the macro level, the presence of chloride ions reduced the corrosion resistance of the stainless-steel passive film, but did not cause corrosion. On the micro level, chloride ion interfered with the phase transformation of the passive film, increased Cr oxides and decreased the loose Fe3 + oxides. From the atomic view of point, the incorporation of chloride into the passive film was mainly due to the higher adsorption energy of Fe2O3 and Cr2O3 with chloride ion, increasing the reactivity of passive film. The presence of Mo in the outer layer of passive film presented a much lower adsorption energy of chloride compared with Fe2O3 and Cr2O3, impeding the ingress of chloride ion in the inner layer. Density functional theory (DFT) calculation complimented the knowledge of interaction of chloride ion with the passive film.

Pullout behavior of recycled macro fibers embedded in ultra-high performance seawater sea-sand concrete

Recently, an eco-friendly ultra-high performance seawater sea-sand concrete (UHPSSC) has been developed using the recycled macro fiber (REF) processed from waste wind turbines, which is more suitable in remote islands and can address the corrosion issue of concrete structures with steel reinforcements. The interface bond of the UHPSSC/macro fiber is lack of investigation and a significant factor influencing the tensile characteristics of macro fiber reinforced UHPSSC. In the present study, the pullout test of the single macro fiber was conducted to investigate the bond behavior of such interface. The test variables included the macro fiber width (4, 6, and 8 mm), the embedded length (5, 10, and 15 mm), and the type of matrix. Then, the local bond-slip relationship at the fiber/UHPSSC interface was obtained by finite element analysis (FEA) to provide a more precise display of interface bond mechanisms. The results revealed that the bond of UHPSSC/macro fiber was stronger with increased fiber embedded length and width due to the greater frictional interactions and better overall integrity of fibers. Additionally, the FEA method proposed here to obtain the local bond-slip relationship was reliable and effective. This study could serve as a basis for further research on the tensile properties of UHPSSC reinforced with macro fibers.

Surface modification of fibres with silane for enhancing the durability of FRP composites as reinforcement for seawater sea sand concrete (SWSSC): A review

This review discusses the necessity of surface modification to effectively use fibre-reinforced polymers (FRPs) as reinforcements for seawater and sea sand concrete (SWSSC). FRPs can be a viable reinforcement material for SWSSC as an alternative to the traditional carbon steel reinforcement that will suffer unacceptably high rates of corrosion due to the very high chloride content of the SWSSC environment. FRPs exhibit mechanical properties similar to steels but suffer insignificant degradation/corrosion due to chloride. However, the fibres in certain FRPs (such as basalt FRPs and glass FRPs) suffer degradation due to attack by the alkaline environment of concrete, causing degradation in fibre-matrix interfacial strength and loss of FRPs’s overall mechanical strength and durability. Therefore, fibres used in such FRPs require suitable surface modification to ameliorate their degradation, enabling their practical use as reinforcements of SWSSC. While carbon fibre-reinforced polymers (CFRPs) demonstrate superior resistance to alkali-induced degradation, their widespread use in large-scale civil engineering is hindered by high costs. In this review, more economic alternatives, i.e., basalt fibre-reinforced polymers (BFRPs) and glass fibre-reinforced polymers (GFRPs) are critically reviewed. To enhance the durability of FRPs and mitigate alkali-induced degradation of the basalt/glass fibres, suitable surface modifications are necessary to safeguard the mechanical properties of FRPs. Underpinned by a comprehensive discussion on the necessity of surface modification of fibres for the use of FRPs in SWSSC environment, this review focuses on the potential of advanced approaches for surface modifications of the fibres, i.e., coatings of silanes, and silanes impregnated with graphene nanoplatelets (GNPs), graphene oxide (GO) and its functionalised derivatives or metal oxides (such as SiO2, ZrO2, Al2O3, TiO2 and CeO2). This review critically discusses the opportunities for suitable surface modification of basalt and glass fibres for enabling the durable use of FRPs as reinforcements for sweater sea sand concrete.

Experimental study on seismic performance of GFRP and highly ductile stainless steel hybrid reinforced concrete columns

To enhance the deformation and energy dissipation capacities of FRP-reinforced concrete structures, this study explores the seismic behavior of seawater and sea sand concrete (SSC) columns reinforced hybrid with GFRP and high ductile stainless steel. It involved designing seven hybrid-reinforced column specimens and one GFRP-reinforced specimen, followed by low-cycle reversed loading tests. This study analyzed the impact of the reinforcement ratio of stainless steel (SS) bars to GFRP bars (ρss/ρGFRP) and the axial compression ratio (μN) on the seismic performances including failure modes, hysteresis curves, load-lateral drift ratio envelope curves, ductility, energy dissipation, residual displacement, and stiffness degradation. Experimental findings indicated that at an axial compression ratio of 0.1, the failure mode of the hybrid-reinforced specimens was primarily governed by flexural-shear behavior. Initially, the specimens exhibited a flexural response up to the yielding displacement but ultimately failed in shear. Compared to columns reinforced only with GFRP, the hysteresis curves of the hybrid-reinforced specimens were significantly fuller, suggesting superior ductility and energy dissipation capacities of the latter. As the ratio of stainless steel to GFRP reinforcement decreased and the axial compression ratio increased, the specimens displayed more pronounced shear failure characteristics. Additionally, the results showed that GFRP longitudinal reinforcement underwent shear fracture or partial fiber rupture due to the combined effects of shear deformation within the core concrete and the confinement provided by stirrups, leading to shear failure of the core concrete. Overall, the findings demonstrate that hybrid-reinforced concrete columns possess enhanced seismic performance relative to those reinforced only with GFRP bars.

Study on mechanical properties and anti-erosion performance of fiber reinforced seawater sea sand concrete

In order to study the mechanical properties of seawater sea sand concrete and the durability damage law of seawater sea sand concrete under the action of seawater erosion, corresponding specimens were prepared and subjected to cube compressive strength, flexural strength, and dry-wet cycle tests by taking the volume dosage of glass fibers and polyvinyl alcohol fibers as variables. The test combined SEM scanning and EDS to analyze the microstructure of fiber-reinforced seawater sand concrete, and established a model based on the two-parameter Weibull probability distribution. The results show that the fiber has a significant effect on improving the mechanical properties and erosion resistance of seawater sand concrete. When the total volume content is 0.3% and the mixing ratio is 1:1, the improvement effect is the best. The maximum increase in cubic compressive strength was 24.2%; the maximum increase in flexural strength was 38.8%. After the specimens were subjected to wet and dry cycles for 360d, the maximum reduction in mass loss rate was 41.23%; the maximum reduction in strength loss rate was 27.55%. As observed from the microscopic images, the main disadvantage of SSC is that the salt crystallization and swelling matter produced by the erosion ions will weaken the bond between aggregate and mortar, resulting in defects in the interfacial transition zone (ITZ). Under the action of dry-wet cycles, the alternating dry-wet forces, the expansion pressure generated by expansive substances and the crystallization pressure generated by salt crystallization will change the microstructure, and therefore the damage of the specimen will deepen with the extension of erosion time. The microscopic images also show that the doping fibers can improve the internal integrity and compactness of the matrix, thus significantly improving the mechanical properties and durability of seawater sea sand concrete. In this test, a damage model was established based on the two-parameter Weibull distribution model, and the damage law between strength loss and dry-wet cycles was fitted, which provides a favorable basis to study the damage of seawater sea sand concrete under wet-dry cycling.

Early Corrosion Behavior of Cr10Mo1 Alloy Corrosion-Resistant Steel Bars in Seawater–Sea-Sand Concrete

Early Corrosion Behavior of Cr10Mo1 Alloy Corrosion-Resistant Steel Bars in Seawater–Sea-Sand Concrete

Effect of tie parameters on strength and ductility of concrete columns reinforced with hybrid steel-fiber reinforced polymer (FRP) composite bars

Using hybrid reinforcement scheme, comprising steel-FRP composite bar (SFCB) and FRP tie, holds great promise in developing seawater sea-sand concrete (SSC) columns with high strength and ductility for marine infrastructures. However, the impacts of FRP tie configurations on hybrid-reinforced SSC columns have not been thoroughly investigated, which hinders their application. To fill this research gap, this study conducted axial compression tests on hybrid-reinforced SSC columns to assess the impacts of tie type, tie size, tie spacing, and tie size/spacing configuration. The failure mechanism of columns, compressive contribution of SFCBs, and confinement mechanism of FRP ties were revealed. The results show that within the tie spacing limit, the failure mode, elastic modulus, yield strength, and ultimate strength of SFCBs are similar. Longitudinal SFCBs effectively resist compression until concrete crushing, providing considerable compressive contributions. However, the confinement efficiency of pultruded FRP ties is limited by the slip of lap splice and the inferior bent portions. In contrast, the closed-type FRP ties exhibit significantly higher confinement efficiency, which increases the load capacity and ductility of columns by 13.6% and 82.8%, respectively. The tie spacing limit was determined and a prediction model of load capacity was proposed based on theoretical analysis and experimental validation.

Modifying effects and mechanisms of superfine stainless wires on microstructures and mechanical properties of ultra-high performance seawater sea-sand concrete

Modifying effects and mechanisms of superfine stainless wires on microstructures and mechanical properties of ultra-high performance seawater sea-sand concrete

Study of endogenous chloride ion content on the behavior of steel bar depassivation in sea sand concrete

In this study, we investigated the chloride concentration in sea sand that induces corrosion in steel bars, as well as the corrosion mechanisms of steel bar within sea sand concrete. Different analytical techniques indicated that the chloride concentration for steel bar corrosion in sea sand concrete was 0.03 % (when the water-binder ratio was in the range of 0.4–0.6). First, the calcium silicate in sea sand concrete reacted with Fe3+ to reduce the compactness of the oxide layer and increase the corrosion risk of steel bars. Second, as the water-binder ratio and chloride concentration gradually increased, the loose structure of the passive film increased, and the relatively dense structure decreased, which made it easier for chloride ions to penetrate the outer layer of the passive film to erode the steel matrix. Besides, the reaction of chloride ions with C3A to form Friedel's salt optimized the pore structure and reduced the content of free chloride ions. However, the adverse effect of chloride ions on the passive film of steel bars exceeded the beneficial impact of porosity reduction. These findings allow us to better apply sea sand to improve the sustainable development of environment.

Novel insights on the setting process, hardened properties, and durability of sustainable ultra-high-performance seawater sea sand concrete

Using seawater and sea sand to prepare concrete could effectively alleviate the shortage of freshwater and river sand resources and promote the sustainable development of concrete. However, the current research on the setting process, hardened properties, and sustainability of ultra-high-performance seawater sea sand concrete (UHPSSC) remain considerably limited. In this paper, the UHPSSC was designed to mitigate the autogenous shrinkage and enhance the sustainability, and the effect of seawater, untreated and desalinated sea sand on the setting process, mechanical properties, durability, and sustainability was explored by various tests. Results show that the abundant ions (e.g., Cl- and SO42-) in seawater and untreated sea sand promote the dissolution and nucleation of cement, accelerating the hydration process, and seawater provides a high pH hydration environment, which enhances the pozzolanic reaction activity of silica fume and fly ash. This leads to the enhanced flexural and compressive strengths at early age, reduced flowability, and increased autogenous shrinkage. Although the seawater and untreated sea sand considerably alleviate the natural raw materials consumption, the mechanical performance at 28 d and durability are reduced, thereby decreasing the sustainability index by 7.8 %. The desalination treatment of sea sand decelerates the hydration process of UHPSSC with untreated sea sand due to the lower ion content in desalinated sea sand. The application of desalinated sea sand mitigates the adverse impact of untreated sea sand on the workability, mechanical properties, and durability. However, this desalination process requires more energy and freshwater consumption, thereby decreasing sustainability index. The fly ash incorporation could improve the workability of UHPSSC, and decrease the autogenous shrinkage value by 17.9 %. Moreover, it mitigates the environmental effect without compromising the mechanical properties and durability, leading to an impressive 42.8 % improvement in sustainability. Durability assessment reveals that the prepared UHPSSC specimen maintains outstanding mechanical properties even after 360 d of exposure to severe marine environment, indicating its excellent durability. This paper provides novel insights for achieving a cleaner and more sustainable concrete production.

Practicability and fundamental performance of alkali treated raw bamboo fiber reinforced high performance seawater sea sand concrete

In pursuit of sustainable development, there has been an increasing amount of research on plant fiber reinforced concrete and seawater sea sand concrete in recent years. In this study, a new type of alkali treated raw bamboo fiber reinforced high performance seawater sea sand concrete (ABFRHPSSC) was suggested, with its practicability evaluated and its fundamental performance investigated. The practicability was evaluated through fiber tensile test, water absorption test, single fiber pull-out test, and degraded fiber characterization test. The fundamental performance, including flowability, mechanical performance, pore volume distribution and three-dimensional distribution of pores and raw bamboo fibers, were then investigated when fiber content and length were used as two parameters. The results showed that the alkali treatment of raw bamboo fibers could increase their tensile strength and elastic modulus, reduce their water absorption, improve their bond performance, and ensure their degradation stability. The fiber content and length had significant effects on the fundamental performance. A fiber content of 0.5 % and a fiber length of 12 mm resulted in relatively optimal mechanical performance while ensuring satisfactory flowability and uniform fiber distribution. At this point, compared with plain high performance seawater sea sand concrete (HPSSC), the compressive, splitting tensile, and flexural strengths increased by 20.1 %, 33.2 %, and 33.6 %, respectively, and the pores were refined. Therefore, ABFRHPSSC has a promising future as a new environmentally friendly material.

Experimental investigations on the flexural behavior of compression-cast seawater sea-sand concrete beams reinforced with CFRP bars

To address the corrosion problems, environmental concerns, and achieve green and sustainable civil engineering practices, this study designed several compression-cast seawater sea-sand concrete (SSC) beams reinforced with corrosion-resistant carbon fiber-reinforced polymer (CFRP) bars (i.e., FRP-SSC beams) and their flexural behavior was experimentally investigated through four-point bending tests. Twelve FRP-SSC beams were designed, including three normal-cast and nine compression-cast ones. The critical parameters included the concrete casting forms, water-to-cement (w/c) ratios, and reinforcement ratios of CFRP bars (ρf). Effects of the concrete casting methods, w/c ratios, and ρf on the flexural responses of FRP-SSC beams were comprehensively studied. In addition, the flexural theorems were used to derive the prediction models of the equivalent stress block parameters (i.e., εcm, α1, and β1) and flexural strength (Mu) of compression-cast FRP-SSC beams. Moreover, based on the experimental results, effectiveness and accuracy of the proposed flexural strength design models were verified by using the existing design specifications. Finally, the results indicate that, (1) compression-cast FRP-SSC beams with the larger ρf (1.78 %) exhibited bending failure featured by compression concrete crushing, whereas that with the smaller ρf (0.75 %) shown splitting failure; (2) The cracking moments of compression-cast FRP-SSC beams increased significantly owing to the higher compressive strength and elastic modulus of compression-cast concrete (CCC); (3) Because of the pronounced brittleness of CCC, the improvement of the ultimate flexural capacity of compression-cast FRP-SSC beams was limited; (4) Under the same moment level, the maximum crack widths of compression-cast FRP-SSC beams were smaller than their normal-cast counterparts; and (5) the proposed flexural strength design models could yield more accurate, safer, and conservative predictions of flexural strength for both normal- and compression-cast FRP-SSC beams.

Multi-technique analysis of seawater impact on the performance of calcium sulphoaluminate cement mortar

The construction of offshore islands and reefs requires the development of new seawater sea-sand concrete materials. This study investigated the impact of seawater on the performance of calcium sulphoaluminate (CSA) cement mortar, with mechanism analyses by the acoustic emission (AE) and digital image correlation (DIC). For all uniaxial compression tests, cumulated AE, average AE frequency, rise angle, b-value, and βt coefficient were considered to perform the failure analysis. In addition, other techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDS) were also employed to highlight the effects of seawater on the hydration products and microstructure of the CSA cement. The results show that seawater not only promotes the formation and growth of ettringite (AFt) but also interacts with cement hydration products to produce Friedel’s salt and various gel formations. Compared to freshwater mixing (0 %), using seawater mixing at normal concentrations (3.3 %) enhances the compactness of the CSA cement, thereby improving the strength and ductility of the CSA mortar. Specifically, the peak load increases from 77 kN to about 86 kN when mixed with seawater at normal concentration, whereas higher seawater concentrations (6.6 %, 9.9 %) resulted in a slight decrease in strength of the CSA mortar, with the peak load reaching approximately 80 kN, yet the ductility is enhanced, as evidenced by the softening post-peak branch of the loading curve. Additionally, AE bursts have a strong correlation with the fracture of the CSA mortar, which can also be forecast by the AE time-scaling coefficient βt. Therefore, when constructing oceanic island and reef foundations, this type of seawater sea-sand concrete is preferred due to its improved ductility and strength, which enhances the structural integrity of marine constructions and provides early warning for effective marine disaster prediction.

Durability of SFCB reinforced low-alkalinity seawater sea sand concrete beams in marine environment

Seawater sea-sand concrete (SWSSC) provides an alternative to normal concrete, while Steel-FRP Composite Bars (SFCB) offer corrosion resistance in offshore and marine structures. Despite their benefits, the long-term performance of SFCB-reinforced SWSSC structures remains under-explored. This study evaluated the durability of such beams, particularly focusing on the effects of using Portland cement versus low-alkalinity calcium sulphoaluminate (CSA) cement. The investigation involved tensile and pull-out tests conducted on SFCB, and flexural tests conducted on the beam components after accelerated marine environmental exposure over periods ranging from one to six months. Results highlighted that SFCB embedded in low-alkalinity CSA cement exhibited improved retention of tensile strength, elastic modulus, and bonding strength by 32.0 %, 39.1 %, and 56.7 % respectively, compared to that embedded in normal Portland cement concrete. Microstructural analyses showed much less hydrolysis of the resin matrix and shallower corrosion of the basalt FRP (BFRP) cover on the SFCB. Furthermore, flexural tests demonstrated superior cooperative performance between low-alkalinity CSA concrete with SFCB in beam components, showing only marginal degradation in crack density, crack strength, and yielding points. The ultimate failure load of beams made with CSA concrete was 1.89 times higher than those made with normal SWSSC after 6 months of exposure. These results underscore the potential of low-alkalinity concrete in improving the long-term durability and structural performance of SFCB-reinforced marine concrete infrastructures.

Study on the Effect of Fly Ash on Mechanical Properties and Seawater Freeze–Thaw Resistance of Seawater Sea Sand Concrete

When using seawater and sea sand as mixes, the mechanical properties and durability of concrete are adversely affected because the raw materials themselves contain harmful ions. Fly ash is the tailings formed in the process of industrial production, the use of which does not require the burning of clinker, reducing CO2 emissions. Moreover, it belongs to a new type of cementitious materials with low emissions and high environmental protection. Fly ash enhances the properties of concrete and reduces the effect of harmful ions on concrete. Based on the above considerations, the corresponding specimens were prepared and subjected to cubic compressive strength, flexural strength, and seawater freezing and thawing resistance tests by using fly ash admixture as the main variable. A combination of macro-analysis and micro-analysis was used to investigate the effect of fly ash on the performance of seawater sea sand concrete. The results showed that fly ash significantly enhanced the mechanical properties and resistance to seawater freezing and thawing of seawater sea sand concrete. The best improvement in compressive strength and resistance to seawater freezing and thawing was achieved at a substitution rate of 20%. The maximum increase in compressive strength was 13.22%. The maximum reduction in mass loss rate was 57.26% and the strength loss rate was 43.14% after the specimens were subjected to seawater freezing and thawing 75 times. The maximum enhancement in flexural strength was 17.06% for a substitution rate of 10%. Through microanalysis, it can be seen that the incorporation of coal ash can enhance the compactness of concrete through the microaggregate effect as well as the volcanic ash reaction to promote the secondary hydration reaction, so as to strengthen the seawater freeze–thaw resistance of seawater sea sand concrete. Finally, the damage prediction model established using the mean GM (1, 1) model of gray system theory meets the requirements of the first level of prediction accuracy and can accurately predict the damage of seawater sea sand concrete under seawater freezing and thawing.

Shear behavior of seawater sea-sand concrete beams reinforced with BFRP bars after seawater dry-wet cycling

The shear behavior of 27 basalt fiber-reinforced polymer reinforced seawater sea-sand concrete (BFRP-SSC) beams after seawater dry-wet cycling was comprehensively investigated. Parameters considered included stirrup diameter and spacing, shear span-to-depth ratio, stirrup surface treatment, cycling duration, concrete cover thickness, and seawater temperature. Results indicate that seawater dry-wet cycling increases cracking load and decreases bending stiffness in BFRP-SSC beams. Increasing shear span-to-depth ratio from 1.55 to 2.35 led to load reductions of 31.3 % and 49.7 % at 6.5 mm mid-span deflection. Seawater dry-wet cycling, particularly temperature and duration, significantly impacts the mechanical properties of stirrups. This results in diminished shear contribution and reduced efficacy in inhibiting diagonal crack propagation, leading to a shift in beam failure mode from diagonal compression failure to shear compression failure and diagonal tension failure. Increasing cycling duration from 60 to 120 days decreased tensile strength retention by 19.1 % and 33.3 % respectively. Based on experimental data, Arrhenius theory, and the time shift factor (TSF) method, a predictive model was developed for the shear capacity retention of beams subjected to seawater dry-wet cycling. Results indicate that after 100 years in a tidal environment (70 % and 90 % relative humidity), shear capacity damage factors of 0.77 and 0.52, respectively, can be applied to account for the impact of seawater dry-wet cycling on the shear capacity of BFRP-SSC beams.

Investigation of the Tensile Strength of Sea Sand Concrete Against the Compressive Strength of the Plan

The availability of sea sand on the beach of Ujung Tape Pinrang is in very large quantities that can be used as materials in making concrete. The purpose of the study is to analyze the characteristics of beach sand, compressive strength and tensile strength produced. An experimental research method in the Civil Engineering Laboratory, University of Muhammadiyah Parepare with a treatment system for ordinary water immersion and analysis of the characteristics of concrete mechanical properties using a compression machine test. The results of the study at the maintenance age of 28 days with a planned compressive strength of 20 MPa produced a compressive strength of 28.29 MPa and a tensile strength of 7.78 MPa, a planned compressive strength of 24 MPa resulted in a compressive strength of 29.98 MPa and a tensile strength of 8.22 MPa, and a planned compressive strength of 28 MPa produces a compressive strength of 31.40 MPa and a tensile strength of 8.44 MPa. The results of the study on compressive strength and tensile strength showed an increase in each increase in planned compressive strength.

Corrosion Resistance of Cr10Mo1 Alloy Corrosion-Resistant Steel in Seawater–Sea Sand Concrete Pore Solution

Corrosion Resistance of Cr10Mo1 Alloy Corrosion-Resistant Steel in Seawater–Sea Sand Concrete Pore Solution