Sufficient Reinforcement Research Articles

Refined strength prediction of concrete 2D bottle-shaped struts

For better strength prediction using strut-and-tie models (STM), it is essential to use reliable strength parameters of the model components; e.g., struts, ties, and nodes. Among all the elements of the STM, the strength of the bottle-shaped struts is not well quantified. The purpose of this study is to develop more accurate formulas for the calculation of the effectiveness factors for 2D bottle-shaped struts, that are unreinforced, reinforced with minimum reinforcement, and reinforced with sufficient transverse reinforcement. The nonlinear finite element analysis, with the aid of the software ABAQUS, has been utilized in this study, which has been verified against experimental tests. The study has been carried out for grades of concrete varying from 20 to 100MPa, and for bearing plate to width ratio varying from 0.1 to 0.9. The obtained formulas for the effectiveness factors of bottle-shaped struts are functions of the concrete strength, which is not the case with the ACI 318-19 provisions. These formulas have been verified against experimental tests and have been compared with the ACI 318-19 provisions. The predictions based on these formulas are more accurate than those based on the ACI 318-19 provisions. Also, the results from these formulas are always on the safe side. On the other hand, the ACI 318-19 provisions lead to unsafe results in the case of high-strength concrete and very conservative results for the case of unreinforced struts from normal-strength concrete.

Ductile design and experimental validation of anchorage strengthening at headed rebar in RC tee connections

Mechanical headed anchorage is widely used in reinforced concrete building construction because it is easy to install and can provide more space for concrete pouring at congested joint regions. At T-shape beam-column joints (hereafter Tee connections) at the roof floor, longitudinal rebar of the column is located outside the beam core, which may cause premature failure at the headed anchorage. Based on a design method for preventing the anchorage failure of headed longitudinal rebar by arranging the anchorage reinforcement, specimens were designed and experimentally validated in this study. The anchorage reinforcement covered anchorage-strengthening hoops and anchorage-strengthening ties arranged at the bottom of the mechanical devices, whose amounts were determined by force equilibriums at the anchor heads. The test results revealed that when sufficient anchorage reinforcement was provided based on the design method, the anchorage failure of the headed rebar in Tee connections at the roof floor could be prevented not only for weak-beam but also for weak-column type specimens. Conversely, anchorage failure was observed in specimens containing no/insufficient anchorage reinforcement. The theoretical requirement for anchorage reinforcement was found to be effective in preventing anchorage failure of column headed rebar in Tee connections based on the hysteretic behavior, failure mode, energy dissipation capacity, equivalent viscous damping, and drift capacity beyond 4.0% rad of the specimens satisfying the requirement.

Centrifugal Modeling of Geo-synthetics Reinforced Roadbed under Cyclic Loading Condition

The cyclic load of overload vehicles will cause uneven deformation of the roadbed, leading to serious safety accidents. Geo-synthetics can effectively restrict the roadbed as a type of reinforcement. However, it is not clear how to arrange geo-synthetics for a good balance between the economic benefits and sufficient reinforcement. A series of centrifuge model tests of geo-synthetics reinforced roadbed are carried out under the cyclic loads. The deformation and reinforcement effect are investigated by considering the different geo-synthetics spacing. The results show that geo-synthetics effectively restricts the roadbed deformation. The reinforcement effect of geo-synthetics decreases with the increase of depth along the loading center. The geo-synthetics reinforcement effect is enhanced by decreasing the geo-synthetics spacing. The cyclic loads only induce deformation within a limited zone in the roadbed. As the geo-synthetics spacing decreases, the depth of the deformation zone decreases while the horizontal width increases.

Value aspect in forming the foundations of information culture in preschoolers

The purpose of the research described in the article is to consider the values and imperatives that underlie the formation of the information culture of preschool children. The research methods were the study and analysis of psychological, pedagogical and philosophical literature, forecasting and reflection. Based on the results of the study, the concept of antifragile education was proposed, its methodological basis, principles and rules were determined. The practical significance of the results obtained lies in determining the components of the formation of the value basis of the preschool information culture preconditions: cognitive (the process of cognition of adequate actions in the digital space in the process of self-realization; the ability to select criteria for ranking information; awareness in the field of digital space threats that contradict imperatives and impede self-realization), behavioral with sufficient emotional and volitional reinforcement (to plan and perform a conscious system of actions), motivational and value (a conscious system of actions for self-realization in accordance with imperatives). The study revealed that the issue of personal self-identification in the redundant digital space has not been sufficiently studied. It is necessary to introduce the principles of antifragile education and continue the awareness and development of the components of the formation of the value basis of the preconditions of the information culture of preschoolers. The concept of antifragile education can form the basis of the work of teachers, starting from the level of preschool education, and the spiritual and moral values that form the basis of the concept can be very important for parents of preschoolers. For the first time, a concept is proposed that is designed to form and maintain imperatives in children, allowing for self-identification and spiritual and moral self-realization in the context of the formation of information culture of preschoolers. As the conclusions, the use of digital technologies in education was noted, and at the same time the issue of introducing the principles of antifragile education for the spiritual and creative self-realization of the individual in the new global international digital space of human life is being actualized.

Seismic performance of assembly joints between HSPC beams and concrete-encased CFST columns

In this study, an assembly joint between a hybrid H-steel precast concrete (HSPC) beam and concrete-encased concrete-filled steel tubular (CFST) column was developed for precast composite structures. The HSPC beam was designed with a novel configuration to connect to the concrete-encased CFST column through a cantilever H-steel beam. To investigate the effectiveness of the developed joint, reversed cyclic load tests were conducted on three full-scale exterior subassemblies with different types of cantilever beams: original, reduced beam section (RBS) and opening in beam web (OBW). The seismic performance of the developed joints was analysed comprehensively based on the failure pattern, hysteresis curve, stiffness degradation, ductility, and dissipated energy. The specimen with the RBS steel beam exhibited a stable hysteretic behaviour up to 4.75% of drift ratio and remarkable ductility, and the cumulative dissipated energy was up to 8.8 times that of the original specimen. However, the improvement in the specimen with the OBW steel beam was insignificant compared with that in the original specimen. Hence, the developed joint with the RBS steel beam exhibited more satisfactory seismic behaviour in terms of the capability to relocate the plastic hinge to the required. This could be applicable in high seismic zones. The seismic performance of the developed joints was affected significantly by a reduction in the reinforcement ratio of the bars transferring the bending stress between the H-steel and RC beams. Therefore, simplified formulas for ensuring a sufficient reinforcement ratio of the bars were proposed and validated through tests.

Investigation of additive incorporation on rheological, microstructural and mechanical properties of 3D printable alkali-activated materials

This study investigates the addition of Poly-vinyl Alcohol (PVA) fibres and attapulgite nanoclay to alkali-activated materials (AAMs) with the aim of enhancing the mechanical performance and optimizing the printability and buildability of AAMs. The fresh properties of six mix formulations, including flowability, slump values, rheology, shape retention, and extrusion window, were evaluated. The best performing mixes, that exhibited optimal fresh properties, were 3D printed, and their mechanical performance, microstructure, and buildability were investigated. The addition of 1 wt.-% attapulgite nanoclay (i.e. A-1) showed the desirable fresh properties required for 3D printing, as well as providing sufficient mechanical reinforcement to the samples. The 3D printed A-1 samples showed an improved flexural and compressive strength by 43% and 20%, respectively, compared to both the casted and printed control mixes. Moreover, microstructure analysis, including SEM, Rapidair measurement, and micro-CT, provided evidence of the compatibility by showing the lowest pores anisotropy and mixture homogeneity, between attapulgite and AAMs.

Magnetically active response of acrylonitrile-butadiene-rubber-based magnetorheological elastomers with different types of iron fillers and their hybrid

In this study, two types, namely carbonyl and electrolytic iron particles with different filler structures, and their hybrid (1:1 ratio) were investigated for the magnetically active responsive properties in acrylonitrile butadiene rubber (NBR)-based magnetorheological elastomers (MREs). The anisotropic MREs were prepared by solvent mixing and applying a magnetic field during cross-linking of rubber. A stronger magnetic effect on stress-relaxation was found for smaller and round shape carbonyl iron particles filled compounds compared to irregular electrolytic and hybrid iron filler-containing MREs. The carbonyl might be the better choice for smooth damping due to sufficient reinforcement and strong magnetic responsive properties. Bigger and irregular electrolytic iron particles with higher filler content can be used for vibration absorbers due to improved stiffness and magnetic properties. However, the hybrid filler containing regular and irregular particles with widely varied sizes should be avoided due to the inferior compressive modulus and lower magnetic effect.

The influence of the kinematics of rough surface engagement on the transfer of forces in cracked concrete

One of the most instrumental aspects governing the response of structural concrete at ultimate limit state refers to the possibility of developing smeared cracking patterns within a member (associated normally to the presence of sufficient reinforcement for control of cracking) or whether failures are associated to localization of strains in a single crack. In the former case, the strains are smeared. New cracks can develop at different orientations and stress redistributions occur in a controlled manner. These cases are governed by equilibrium and by material yield conditions and can thus be designed according to limit analysis. The response corresponding to crack localization is however associated to potentially brittle failures, occurring by a sudden opening and sliding of a critical crack, and does not normally allow for controlled redistributions of stresses. In this case, the shape and kinematics of the critical crack are governing for the strength of the member and design methods based on limit analysis are generally not applicable.In this paper, a discussion on the transfer of forces in cracked concrete is presented, allowing to consider in a consistent manner both cases where smeared or localized cracking occur. This is investigated by means of the stress state developed in the vicinity of a localized crack and accounting for equilibrium, kinematics and material damage conditions. The approach presented allows for a comprehensive view of the phenomenon of transfer of forces through cracked concrete and to describe cases governed by the material strength or by friction conditions depending on the crack kinematics. On this basis, the implications for shear design of concrete members are discussed.

Two-way shear strength of reinforced concrete transfer slab-column connections

In high-rise wall-type residential buildings, thick RC transfer slabs have been widely used for parking space or public space. Despite the different behavior from thin RC flat slab, design methods for thin RC flat slab are applied to the thick RC transfer slab, due to the limited literature on the two-way shear behavior of RC transfer slab systems with small shear span-to-depth ratio. In the present study, concentric compression tests were performed on eight RC transfer slabs with small shear span-to-depth ratio to investigate the two-way shear strength. The test parameters were the concrete strength, shear span-to-depth ratio, slab thickness, and reinforcement ratio of the slab. The two-way shear strength, deformation capacity, failure mode, and strain distribution of slab rebars of the slab specimens were evaluated. The test results showed that the use of high-strength concrete or large reinforcement ratio increased the two-way shear strength of the transfer slab specimens. However, the transfer slab specimen having large slab thickness without sufficient reinforcement was susceptible to punching shear failure, showing insignificant strength increment. The two-way shear strengths of the test specimens were compared with the predictions of the current design method and the strut-tie model.

Numerical investigation of reinforcement pullout resistance effects on behavior of geosynthetic-reinforced soil (GRS) piers

In this study, three-dimensional numerical analyses were carried out to investigate the effects of reinforcement pullout resistance including facing connection strength on the behavior of geosynthetic-reinforced soil (GRS) piers under a service load condition. Three different piers were investigated in this study, which simulated different levels of reinforcement pullout resistance. Each pier had two cases with different reinforcement stiffness J and reinforcement spacing Sv but the same ratio of J/Sv. Numerical results showed that reinforcement pullout resistance had a significant effect on the behavior of GRS piers. When the pullout mode prevailed, the case with small Sv and low J had smaller lateral facing displacements and vertical strain of the pier under the same applied pressure as compared to the case with large Sv and high J when the ratio of J/Sv was kept constant. When the pullout mode did not prevail, two cases with the same ratio of J/Sv showed similar performance despite different combinations of Sv and J were used. To more effectively mobilize reinforcement strength and improve GRS pier performance, small reinforcement spacing or high-strength facing connection should be considered when sufficient reinforcement pullout resistance cannot be guaranteed otherwise.

Critical amount of corrosion and failure behavior of flexural reinforced concrete beams

Offshore structures are subjected to chloride ion penetration leading to corrosion of the embedded steel rebars. A tensile steel bar with non-uniform corrosion such as pitting can rupture prior to yielding. In this study, the critical corrosion amount that causes tensile steel rupture in reinforced concrete beams was determined in two parts of work. In the first part, the flexural performance of low-to-highly corroded reinforced concrete beam was investigated. A series of load tests comprising of 44 reinforced concrete specimens, all having a rectangular section, 80 mm wide by 120 mm deep, and the length of 550 mm, were conducted. Each beam was reinforced with one D10 steel bar as the tension reinforcement, one acrylic top reinforcement and sufficient shear reinforcement to avoid shear failure mode. The corrosion in the steel bars was induced with an electrolytic set up with the controlled amount based on Faraday’s law. These bars were extracted from the beams to measure the actual corrosion amount after the test. The results show a sharp reduction in the ultimate load and ductility when the corrosion was over 30%, and concrete crushing was observed at failure. In the second part of the work, tension tests of 17 D10 bars with 0–15% corrosions were carried out to investigate the rupture strain of the bars. The test results show the exponential decay function of the rupture strain as the corrosion increases. The obtained decay function was then used in determining the bending capacity and the failure mode of RC beams. Based on the calculation, the critical amount of corrosion altering the failure mode from yielding to rupture was 15%. Moreover, to reflect uncertainties in the natural process of the corrosion, the variation of the corrosion amount due to the pitting behavior and the rupture strain with the obtained standard deviations of the test data were considered. Accordingly, the lower and upper limits of the critical amount of corrosion were 8–25%, respectively.

DNA DB Operation and Privacy Concerns

DNA가 범죄수사에 활용되기 시작된 이래, DNA DB를 통해 많은 미제사건을해결하고 있고, 보다 많은 사건을 해결하기 위해 DNA DB의 분석마커를 확장하고자 하는 논의가 있다. 외국의 경우 범죄유형, 가족 검색 등 DNA DB의 확대 운영을 통해 많은 사건을 해결하고 있다. 우리나라는 DNA DB제도 도입 초기부터 프라이버시 침해 우려와 DNA 범죄수사의 효용성 주장의 충돌이 첨예하였다. 이에 이 연구는 향후 논의 가능성이 있는 확장된 DNA DB 운영방안에 대해소개하고, 그에 대한 일반국민의 인식을 확인해보았다. 특히, DNA DB의 수록범위 확장에 따른 개인 DNA정보(DNA신원확인정보) 침해와 관련한 우려 수준도 함께 확인해보았다. 여기에는 개인정보보호 관련 연구에서 활발하게 사용되고 있는 프라이버시 염려(수집, 오류, 허가되지 않은 2차 사용, 부적절한 접근) 개념을 활용하였다. 또, 시민의 프라이버시 염려가 DNA DB 확대 운영 인식에어떠한 영향을 미치는지를 알아보았다. 연구 결과, 프라이버시 염려의 하위개념인 수집, 오류, 허가되지 않은 2차사용이 DNA DB 운영에 통계적으로 유의미한 영향을 미치는 것으로 확인되었다. 즉, 수집과 허가되지 않은 2차 사용 염려는 DNA DB의 확대 운영에 부(-) 적 영향이 있었고, 오류 염려는 DNA DB의 확대 운영에 정(+)적 영향이 나타났다. 여기서 오류와 관련한 결과는 프라이버시 역설로 설명된다. 이러한 결과를 바탕으로 이 연구에서는 DNA DB 운영의 사회안전 기능은 물론 개인의 프라이버시 보호를 위한 각종 제도적 장치에 대한 충분한 홍보 강화를 제안하였다.Since DNA began to be used in criminal investigations, many cold cases have been resolved through DNA DB. There is a discussion to expand the DNA marker or DNA DB in order to solve more cases. In foreign countries, many crimes are solved by expanding the DNA DB such as crime type and family search. In Korea, from the beginning of the DNA DB system, the conflict between privacy concerns and the claims on the effectiveness of DNA criminal investigations has been sharp. Therefore, this study introduced an expanded DNA DB operation plan that could be discussed in the future, and confirmed the public s perception of it. In particular, we also checked the level of concern for personal DNA privacy due to the expansion of the coverage of the DNA DB. Here, the concept of privacy concerns (collection, error, unauthorized secondary use, inappropriate access), which is actively used in research related to personal information protection, was utilized. In addition, it examined how citizens privacy concerns have an impact on the perception of expanding DNA DB operations. As a result of the study, it was found that the sub-concepts of privacy concerns, such as ‘collection’, ‘error’, and ‘unauthorized secondary use’, had a statistically significant effect on the operation of the DNA DB. In other words, concerns about ‘collection’ and ‘unauthorized secondary use’ had a negative (-) effect on the expansion operation of the DNA DB, and fear of ‘errors’ had a positive (+) effect on it. Here, the consequences of ‘error’ are explained by the privacy paradox. Based on these results, it was suggested that sufficient publicity reinforcement for not only the social safety function of the DNA DB operation but also various systems for personal privacy protection.

Influence of link spacing on concrete shear capacity: experimental investigations and finite element studies

This paper investigates the influence of varying the spacing of shear reinforcement on the response of six geometrically identical reinforced concrete beams. Each beam was designed with differing longitudinal and transverse reinforcement configurations to provide improved understanding of the importance of providing sufficient shear reinforcement following guidance provided in Eurocode 2. Three different cases of varying transverse reinforcements were tested: one without the presence of shear reinforcement, one with shear reinforcement non-compliant to the design provisions and one where the design of the beams fully complies with the design guidance. In order to verify the experimental results, an open source digital image correlation software was utilised to allow for a computational crack mapping, along with the use of nonlinear finite element analysis software to enable a more thorough investigation of the individual beam response. The results obtained highlighted that shear links non-compliant to Eurocode 2 consequently led to unpredictable modes of failure, whereas beams containing shear links at the required amount and spacings displayed significant improvements in the mode of failure and ductility. Beams with the omittance of shear links resulted in the lowest load capacity, due to the sudden, brittle shear failure.

Investigation of stress-strain relationship for confined lightweight aggregate concrete

Lightweight aggregate concrete (LWAC) is prone to undergo the aggregate fracture, which causes its failure mechanism are significantly different from that of normal weight concrete. The provision of sufficient lateral reinforcement can effectively improve the synergistic effect between the lightweight aggregates and cement matrix, thus enhancing the strength and ductility of LWAC and expanding its engineering applications. This paper presents an experimental investigation on the uniaxial behavior of twelve LWAC columns designed with different amount and configuration of lateral reinforcement. The equations of the feature points needed for the stress-strain model are established by considering the confinement efficiency of the lateral reinforcement and the actual lateral reinforcement stress at the peak point, and are calibrated using the extensive results of the confined LWAC test database. Test results reveal the working mechanism of confined LWAC and further verify the accuracy and applicability of the proposed model.

Mechanical improvement of continuous steel microcable reinforced geopolymer composites for 3D printing subjected to different loading conditions

Sufficient reinforcement is crucial for three-dimensional (3D) printed concrete structures. In this study, continuous and simultaneous micro-cable reinforcing methods are investigated to accommodate the 3D flexible and automatic characteristics of additive manufacturing processes, and to satisfy the mechanical-property requirements for construction applications. Different manufacturing-related micro-reinforcements and printing configurations are designed for 3D printing cable-geopolymers. The specimens were subjected to three different types of loading conditions (compressive, shear, and tensile) to gain a better understanding of the composite behavior. The results revealed interesting behaviors: under compressive loadings, the confinement effect of the micro-cables is fundamental in producing additional strength, ductility, and toughness. The print path must be considered for determining the confinement levels. Micro-cables increase the compressive strength by 50.0% in a certain print path. The shear strength depends primarily on the geopolymer weak planes’ directions between two filaments instead of the embedded cable reinforcements. The tensile response is primarily governed by the micro-cable reinforcements and the configurations, which depend on the print paths. In certain configurations, the micro-cables result in 158% and 43.8 times increase in tensile strength and strain, respectively. This study provides valuable insights into the behavior of 3D-printed geopolymer composites with micro-cable reinforcement, which is necessary for designing and manufacturing complex structures using this novel reinforcement method.

Field-cooled magnetization of Y-Ba-Cu-O superconducting bulk pair reinforced by full metal encapsulation under high magnetic fields up to 22 T

We report on the field-cooled magnetization (FCM) process under magnetic fields of up to 22 T for the stacked Y-Ba-Cu-O (YBCO) bulk pair reinforced by a stainless steel (SUS316) container. On the basis of the numerically simulated mechanical stress in a bulk during FCM, the SUS316 container was designed by the numerical simulation to offer the sufficient hoop stress tolerance to the bulk trapping the magnetic field of 20 T. As a result, we obtained successfully the trapped field, BT, of 15.1 T by FCM from 18 T at 28 K at the center of the YBCO bulk pair. However, the extremely large-scale vortex jumps and large temperature rise occurred suddenly during FCM from a higher field of 22 T at a lower temperature of 23 K, and then a small crack was confirmed at the periphery of “both” YBCO bulks from the distorted contour maps of BT. The simultaneous break of both YBCO bulks probably in spite of sufficient mechanical reinforcement led us to conclude that the thermal instability triggered off the large-scale vortex jumps and large heat generation. The stress concentration induced thermally at the hot spot brought about the cracking.

New design concepts for strengthening of continuous reinforced-concrete beams

The present article is concerned with basic methods of reinforcement of continuous reinforced-concrete beam constructions. The main disadvantages and difficulties in strengthening such load carrying structures have been identified in this academic paper. There has been offered the method of reinforcement of continuous reinforced-concrete beam constructions. Besides, the authors have established the procedure of designing effective continuous reinforced-concrete beams in case of the reinforcement. The basic principle of enforcement of continuous reinforced-concrete beams is proposed in this exploratory development. This principle lies in the fact that it is necessary to find the desired span stiffness of continuous reinforced-concrete beam constructions, which would provide sufficient reinforcement in the reference section of the beams. In this case, there is no need to strengthen reference sections, which is practically impossible to do in most instances without dismantlement of the existing concrete floor slabs. For reinforcement systems designing, it is proposed to use the method of design resistance of reinforced concrete, which uses theoretically, and experimentally confirmed prerequisites and hypotheses. The calculations are made by the iteration method. There has been provided a calculation example of enforcement of continuous reinforced-concrete beam constructions using the proposed method.

The role of patch hybridization on tensile response of cracked panel repaired with hybrid composite patch: experimental and numerical investigation

ABSTRACT This article presents a distinct perspective of structural repair by bonding the hybrid composite patch. A novel hybrid composite patch is prepared from the carbon and glass fibers to repair the cracked panel. Different volume fractions of constituents are maintained to prepare the composite patch with varying stiffness. The elastic constant of the composite patch is derived by applying the rule of hybrid mixture and modified Halpin Tsai equation. The stress intensity factor in the panel and interfacial stresses in the adhesive layer are evaluated to assess repair efficiency and repair durability. Effects of the elastic modulus of the adhesive on the performance of composite patch repair are demonstrated. The load carrying capacity and failure strength are examined for variation in patch stiffness. The disbonded surface morphology is investigated through scanning electron microscopy after failure. The results reveal that the hybrid composite patch provided sufficient reinforcement to reduce the stress intensity and interfacial stresses. Patch hybridization has offered a pragmatic solution and proposed as an alternative patch material to repair the cracked structure.

Classification of failure modes in ductile and non-ductile concrete joints

In reinforced concrete structures, the behavior of beam-column connections has a significant effect on the overall behavior of the structure. Therefore, knowledge of the failure mode in these elements can be essential. In this article, two methods are proposed that can determine the failure mode type of the reinforced concrete joints, those with sufficient transverse reinforcement (ductile joints) and in concrete joints with no or little transverse reinforcement (non-ductile joints), in a probabilistic manner with high accuracy. For this purpose, two classification structures based on a number of classifiers for exterior and interiors concrete joints were utilized to determine the type of failure modes. A collection of laboratory tests were used to create and validate the classifications. It was concluded from the results that the models presented in this paper have the ability to determine the failure mode. The use of these models are simple and do not need any complex calculation. They also can be useful tools in structural engineering problems such as the initial investigation of damages in existing concrete structures or for retrofitting applications.

Flexural Behavior of the Innovative CA-UHPC Slabs with High and Low Reinforcement Ratios

This paper presents an experimental study on the flexural behavior of an innovative CA-UHPC (ultrahigh-performance concrete containing coarse aggregate) slab with high and low reinforcement ratios. A total of eighteen CA-UHPC slabs were tested to failure under the parameters of longitudinal reinforcement ratio, curing method, and maximum aggregate size. Test results indicated that sufficient longitudinal reinforcement should be embedded to prevent the brittle failure and disastrous damage. High ductile failure mode was observed for specimens with high reinforcement ratio compared with specimens with low reinforcement ratio. Instead of extensively crushing as normal strength concrete, delamination failure appeared in the compression zone of the CA-UHPC slabs owing to the fibers’ bridging effect, the yielding of longitudinal reinforcement, and the large expansion of flexural cracks which led to the final failure. The reinforced CA-UHPC slabs demonstrated excellent deformability, and ultimate ratio of deflection to span increased from 1/281 to 1/12 when the reinforcement ratio raised from 0% to 3.45%. Stiffness of the reinforced specimens at the flexural cracking state was about 88% and only approximately 6% at the ultimate state, but nearly 50% of the initial stiffness remained when the longitudinal reinforcements yielded, which indicated superior load resistance ability and excellent postcracking deformability. A new ductility index was proposed to evaluate the postcracking ductility of the CA-UHPC specimens. Finally, test results were compared with the flexural strength predictions of CECS 38-2004, ACI 544.4R, and BS EN 1992.