Reinforcement Rate Research Articles

A parametric study of steel-concrete composite beams with hollow core slabs and concrete topping

The use of industrialized elements results in the speed of execution, it avoids waste of materials, and it meets sustainability requirements. The steel profiles and hollow core slabs are included in this scope. The hollow core slab presents superior quality than cast in-situ structural elements, and it is produced in specific environments with technological control and monitoring. In general, a concrete topping is made for smooth and uniform finishing. Studies addressing the structural behavior of steel-concrete composite beams with hollow core slabs with concrete topping are scarce. The present work aims to investigate the behavior of steel-concrete composite beams with hollow core slabs with concrete topping, considering full and partial interaction. Geometric nonlinear analyses are performed based on experimental tests. The steel-concrete composite beams with hollow core slabs with concrete topping are simply supported and subjected to two points loads symmetrically spaced. The influence of concrete topping (50 mm of thickness), the in situ concrete strength (25 MPa, 30 MPa and 40 MPa), the transverse reinforcement diameter (10 mm, 12.5 mm and 16 mm), the interaction degree (shear connectors spaced at 120 mm, 175 mm and 225 mm), and the steel cross section (W360 × 51, W460 × 74 and W530 × 72) are the parameters investigated. The results are discussed, considering these parameters. It was concluded that the concrete topping increased the strength of the composite beams with precast hollow core slabs, the lower the degree of interaction, the greater the ductile behavior of the composite element as a whole. The in-situ infill concrete strength was directly influenced by the steel cross-sectional area, transverse reinforcement rate and interaction degree. The resistance of steel-concrete composite beams with precast hollow core slabs may vary depending on the transverse reinforcement rate and interaction degree. Ductile behavior was observed for all situations, considering partial interaction.

Effect of utilizing geopolymer fly ash on potential and corrosion rate of reinforcement in high-strength concrete

With the increasing use of high-strength reinforced concretes as a structural element of construction, their resistance to corrosion in environmental conditions needs to be studied. It is well known that cement manufacturing at plants is un-environmental friendly due to plenty of fuel consumption and CO2 emission to the atmosphere leading to greenhouse effect. Therefore, substituting cement with environmentally friendly natural materials and natural wastes become a smart solution. This study aims to measure the potential level and corrosion rate of reinforcing steel in high-strength concrete with variations in cement replacement by geopolymer fly ash, environmental conditions, and concrete covering thickness. Corrosion potential measurement was carried out with the half-cell potential mapping method, while the corrosion rate used the linear polarization resistance method. Data collection was executed every two weeks during eight weeks of immersion. High-strength concrete beams with compressive strength target 70 MPa having dimension 15cm x 20cm x 80cm were substituted with 15% coal fly ash (CFA), 15% palm oil blast furnace slag fly ash (POSFA), and 10% pozzolanic fly ash (PFA) from cement weight. High-strength concrete specimens without fly ash substitution were made as a comparison (HSCWFA). It was installed 4 longitudinal reinforcement 010 mm and 7 stirrups 6 mm with a distance of 10 cm. The concrete covering thickness was 2 cm and 4 cm. Immersion medium uses artificial seawater (3.5% NaCl) and shallow well water. The results showed that specimens resulting in the lowest corrosion rate were PFA, CFA, POSFA, and HSCWFA respectively. Corrosion potential was obtained at low to medium levels, while corrosion rates were at low corrosion level criteria. It can be clearly concluded that the utilizing of a geopolymer fly ash could increase the permeability of high-strength concretes through their higher resistance to the penetration of chloride ions.

Resurgence and downshifts in alternative reinforcement rate.

Resurgence refers to an increase in a previously suppressed target behavior with a relative worsening of conditions for a more recently reinforced alternative behavior. This experiment examined the relation between resurgence and the magnitude of a reduction in the rate of reinforcement for the alternative behavior. Groups of both male and female rats initially pressed a target lever for food on a variable-interval (VI) 30-s schedule. In a second phase, responding to the target lever was extinguished for all groups and pressing an alternative lever was reinforced on a VI 10-s schedule. Next, the rate of reinforcement for alternative behavior was reduced differentially across groups by arranging extinction, VI 80-s, VI 40-s, VI 20-s, or continued VI 10-s reinforcement. Target responding increased as an exponential function of the magnitude of the reduction in alternative reinforcement rates. With the exception that males appeared to show higher rates of target responding in baseline and higher rates of alternative responding in other phases, the overall pattern of responding across phases was not meaningfully different between sexes. The pattern of both target and alternative response rates across sessions and phases was well described quantitatively by the Resurgence as Choice in Context model.

Negative reinforcement rate and persistent avoidance following response-prevention extinction

Persistent avoidance may be influenced by prior negative reinforcement rate (i.e., how effective the response is at controlling threat). In clinical settings, the effectiveness of extinction-based methods for treating anxiety-related avoidance may be impacted by prior reinforcement rate. Here, we conducted a laboratory-based treatment study to investigate the persistence of avoidance following response-prevention extinction (RPE) when prior avoidance had been differentially effective at cancelling shock. Participants in three negative reinforcement rate groups (100%, 50%, and 0%) completed a validated avoidance conditioning paradigm involving Pavlovian fear extinction, RPE, and re-extinction phases. It was hypothesised that partially reinforced avoidance would lead to diminished resistance to fear extinction following response prevention, compared to continuously- or never-reinforced avoidance. Persistent avoidance was related to prior negative reinforcement rate, with higher rates more resistant to extinction. These findings illustrate the role of reinforcement rate in the persistence of avoidance and may aid understanding of treatment relapse.

Resurgence without overall worsening of alternative reinforcement

Three experiments were conducted with pigeons to assess discriminated periods of nonreinforcement as precipitators of resurgence. Each experiment occurred in three phases. In the Training phase, key-pecking was reinforced according to variable-interval schedules that alternated between two response keys (Experiment 1) or were concurrently available on two response keys (Experiments 2a & 2b). In the Alternative-Reinforcement phase, responding to one key was extinguished, while that to the other was reinforced according to tandem schedules. These then were replaced by chained schedules with the same programmed reinforcement rate in the Resurgence-Test phase. Resurgence occurred both when the signaled period of nonreinforcement was a darkened keylight in the terminal link of the chain schedule (Experiment 1) and a darkened keylight (Experiment 2a) or keylight color change (Experiment 2b) in the initial link of the chain schedule. Thus, signaled periods of extinction, without accompanying reductions in reinforcement rate, precipitated resurgence, suggesting that resurgence is not the result of worsening of overall reinforcement conditions, but also occurs when local conditions of reinforcement are worsened.

Preclinical support for the therapeutic potential of zolmitriptan as a treatment for cocaine use disorders

Serotonin 1B receptor (5-HT1BR) agonists enhance cocaine intake in rats during daily self-administration but attenuate cocaine intake after prolonged abstinence. Here we investigated whether the less selective but clinically available 5-HT1D/1BR agonist, zolmitriptan, produces similar effects. Male and free-cycling female Sprague-Dawley rats were trained to lever press for cocaine (0.75 mg/kg, i.v.) or sucrose (45 mg pellet) reinforcement until performance rates stabilized. Rats then received zolmitriptan (3.0, 5.6, and 10 mg/kg, s.c.) prior to testing for its effects on response and reinforcement rates. Under cocaine testing conditions, rats had access to the training dose for the first hour followed by a lower cocaine dose (0.075 mg/kg, i.v.) for the second hour. Zolmitriptan decreased cocaine intake at both cocaine doses and in both sexes even without a period of abstinence and without altering sucrose intake. A separate group of rats underwent identical training procedures and were tested for effects of the selective 5-HT1B and 5-HT1D receptor antagonists, SB224289 (3.2, 5.6, and 10 mg/kg, s.c.) and BRL15572 (0.3, 1.0, and 3.0 mg/kg, i.p.), respectively, alone or in combination with zolmitriptan (5.6 mg/kg, s.c.) under identical cocaine testing procedures as above. The zolmitriptan-induced decrease in cocaine intake was reversed by SB224289 and to a lesser extent by BRL15572, suggesting that the effects of zolmitriptan involve both 5-HT1B and 5-HT1D receptors. Neither zolmitriptan, SB224289, or BRL15572 altered locomotor activity at the doses effective for modulating cocaine intake. These findings suggest that zolmitriptan has potential for repurposing as a treatment for cocaine use disorders.

Optimization of Process Parameters using Taguchi Technique for Drilling Aluminium Matrix Composites (LM6 / B4C)

Due to their abrasive behaviour, metal matrix composites (MMCs) are difficult to machine, so it is necessary to develop a suitable technology for their efficient machining. The ultimate goal of the research is to study the impact of process variables such as reinforcement, drill type, speed and feed rate on the thrust force and burr height during AMCs drilling. Aluminium Matrix Composites were manufactured with LM6 aluminium alloy as matrix and B4C as reinforcement through the low cost stir casting process. Experiments were performed using L27 orthogonal array in a CNC Vertical Machining Centre equipped with cutting tool dynamometer to measure the thrust force and burr-height was measured using vision measuring system. Experimental results demonstrated that this strategy enhances the performance characteristics expected in the drilling phase.

Partikül Boyutunun ve B4C Katkı Oranının Al-B4C Kompozitlerin Mekanik ve Mikroyapı Özellikleri Üzerine Olan Etkisi

In this study, Al-B4C composites were produced with various particle sizes (B4C: 3.5 and 20 µm) and reinforcement rates (B4C%: 1, 3, 6, 9, 12, 15, 30%) by the powder metallurgy method. The apparent density, compressive strength, and Vickers hardness of the composites were determined by Archimedes’ density meter, universal test machine, and micro Vickers hardness measurement device, respectively. The phase and microstructural analysis of the fabricated composites were analyzed using an X-ray diffraction device and scanning electron microscope, respectively. From the test results, the highest micro Vickers hardness (68.8 HV), apparent density (2.61 g/cm3), compressive strength (242 MPa), and minimum porosity (1.4%) were determined at 3.5 µm particle size and 30% reinforcement rate of B4C. The enhancement in Vickers hardness and compressive strength of Al-30%B4C composite was detected as +129.3% and +165.9% compared with pure aluminum.

Boundary conditions of post-retrieval extinction: A direct comparison of low and high partial reinforcement

Research has shown that a single presentation of the conditioned stimulus prior to extinction training can diminish conditioned responses. However, replication has proven difficult and appears to be limited by boundary conditions. Here we tested the boundary condition of memory strength by comparing the effect of reinforcement rate to assess its role in post-retrieval extinction. Eighty university students had undergone a three-day fear conditioning experiment in which two partial reinforcement schedules (40%, 80%) were applied. The findings indicated that both low and high partial reinforcement groups did not demonstrate recovery of conditioned responses after post-retrieval extinction. In contrast, both groups demonstrated significant recovery to standard extinction with significantly greater recovery in the 80% group relative to the 40% group. Additionally, we found that greater physiological arousal during memory retrieval significantly predicted recovery of fear at test phase. We conclude that when compared to a lower partial reinforcement schedule, a higher partial reinforcement resulted in the formation of a stronger memory as indicated by greater physiological arousal during memory reactivation and recovery of conditioned responses after standard extinction, but that it does not function as a boundary condition of post-retrieval extinction. These data are significant because it is the first study to investigate the effect of varying partial reinforcement schedules on fear recovery and add to the body of literature that continue to identify sources of failure in the application of post-retrieval extinction.

The Long-Acting D3 Partial Agonist MC-25-41 Attenuates Motivation for Cocaine in Sprague-Dawley Rats

The dopamine D3 receptor is a prime target for developing treatments for cocaine use disorders (CUDs). In this study, we conducted a pre-clinical investigation of the therapeutic potential of a long-acting, D3 receptor partial agonist, MC-25-41. Male rats were pre-treated with MC-25-41 (vehicle, 1.0, 3.0, 5.6, or 10 mg/kg, intraperitoneal (IP)) five minutes prior to tests of cocaine or sucrose intake on either a progressive ratio schedule of reinforcement or a variable interval 60 s multiple schedule consisting of 4, 15-min components with sucrose or cocaine available in alternating components. A separate cohort of rats was tested on a within-session, dose-reduction procedure to determine the effects of MC-25-41 on demand for cocaine using a behavioral economics analysis. Finally, rats were tested for effects of MC-25-41 on spontaneous and cocaine-induced locomotion. MC-25-41 failed to alter locomotion, but reduced reinforcement rates for both cocaine and sucrose on the low-effort, multiple schedule. However, on the higher-effort, progressive ratio schedule of cocaine reinforcement, MC-25-41 reduced infusions, and active lever presses at doses that did not alter sucrose intake. The behavioral economics analysis showed that MC-25-41 also increased cocaine demand elasticity compared to vehicle, indicating a reduction in consumption as price increases. Together, these results suggest that similar to other D3-selective antagonists and partial agonists, MC-25-41 reduces motivation for cocaine under conditions of high cost but has the added advantage of a long half-life (>10 h). These findings suggest that MC-25-41 may be a suitable pre-clinical lead compound for development of medications to treat CUDs.

Cue duration determines response rate but not rate of acquisition of Pavlovian conditioning in mice.

The duration of a conditioned stimulus (CS) is a key determinant of Pavlovian conditioning. Rate estimation theory (RET) proposes that reinforcement rate is calculated over cumulative exposure to a cue and the reinforcement rate of a cue, relative to the background reinforcement rate, determines the speed of acquisition of conditioned responding. Consequently, RET predicts that shorter-duration cues require fewer trials to acquisition than longer-duration cues due to the difference in reinforcement rates. We tested this prediction by reanalysing the results of a previously published experiment. Mice received appetitive Pavlovian conditioning of magazine approach behaviour with a 10-s CS and a 40-s CS. Cue duration did not affect the rate at which responding emerged or the rate at which it peaked. The 10-s CS did elicit higher levels of responding than the 40-s CS. These results are not consistent with rate estimation theory. Instead, they are consistent with an associative analysis that assumes that asymptotic levels of responding reflect the balance between increments and decrements in associative strength across cumulative exposure to a cue.

Investigation into the dynamic molecular and conductivity mechanisms of piezoelectric ceramics Pb[ZrxTi1−x]O3/epoxy piezocomposites

AbstractThroughout this work, an experimental and theoretical analysis of the molecular dynamics, correlated with the alternating current conductivity σac(ω, T),of unidirectional piezoelectric composites used as actuators and/or sensors in different systems was carried out. The 3D‐representation of the imaginary part M″(ω, T) of the electric modulus shows, apart from the presence of the classical secondary β and the primary α dipolar relaxation processes, the appearance of a new peak attributed to the Maxwell‐Wagner‐Sillars (MWS) interfacial polarization whose amplitude depends on the rate of reinforcement. In our case, since we are usually within the range of fragile materials, the stiffness of the 26% fiber content composite is about 4.5 times greater than that of 13.4% (via the fragility parameter D), shows a less pronounced curvature and the nature of the relaxation times is closer to the Arrhenius type. Due to the high dispersion of the conductivity with the frequency of applied electrical field in the range (1‐104 Hz), Jonscher's “universal power law” has been revised by adding a new term, which takes into account the displacement current density. The ac conductivity adjustment procedure, using the new obtained expression, turns out to be accurate and follows the experimental data reported in the low, high, and even intermediate frequency domains. This theoretical approach allowed us to determine the key parameters (∆ε, τmax,…) unique to each relaxation process, and to demonstrate the MWS interfacial polarization that is directly linked to the adhesion between the PZT fibers and the epoxy resin matrix.

Investigation of surface tension and contact angles for effective polymer binders based on epoxy oligomers and active diluents

Objectives. This study focused on the quantification of the surface tension and the static and dynamic contact angles of epoxy oligomers, active diluents, and their mixtures of various compositions at different temperatures. The active diluents were aliphatic compounds based on glycidyl ethers, namely laproxides and a laprolate of different structure, functionality, molecular weight, and viscosity. Moreover, the preparation of effective polymer binders (matrices) for composites was explored.Methods. In this study, the epoxy oligomers ED-20 and DER-330, laproxides 201B, DEG-1, E-181, and 703, laprolate 301, and their mixtures in various compositions were investigated. Their surface tension and the static and dynamic contact angles were determined by the Wilhelmy plate and ring methods on a semiautomatic tensiometer at different temperatures (20–60 °C). The static contact angle was measured on a thin aluminum borosilicate glass plate, and the dynamic contact angles were determined using an installation for measuring surface tension developed by NPO Stekloplastik.Results. The surface tension and static and dynamic contact angles were obtained for all epoxy oligomers and active diluents, as well as for their mixtures at 20–60 °C. For binders based on systems of epoxy oligomers and active diluents, the impregnation rate of fiber reinforcement was also calculated. The introduction of laproxides or laprolates into the epoxy oligomers led to a decrease in surface tension and contact angles, while the increase in temperature increased the impregnation rate by 10–20 times.Conclusions. The temperature increase from 20 to 60 °C resulted in a decrease in the surface tension of mixed systems of epoxy oligomers and active diluents by almost two times. In addition, the contact angles changed by only 4°–7°, while the impregnation was significantly improved and the corresponding rate increased by 10–20 times.

The mechanical, thermal and sound absorption properties of flexible polyurethane foam composites reinforced with artichoke stem waste fibers

Recently, due to environmental concerns and dependence on depleted resources, the use of renewable resources has become important in the preparation of various industrial materials. The use of natural fibers instead of petroleum-based synthetic fibers traditionally used in the production of composite materials provides many advantages in terms of both environmental and cost. The utilization of agricultural wastes as natural fibers also contributes significantly to the reduction and reuse of wastes, which is one of the objectives of sustainable development. In this study, artichoke stem waste fibers reinforced polyurethane foam composites were obtained. The fibers were treated with alkaline surface treatment at different concentrations (5% and 10%) of sodium hydroxide (NaOH) and durations (5, 10 and 15 min). The optimal alkali method was determined and applied to the fibers and its effect on composites was also investigated. Treated and untreated fibers were combined with polyurethane (PU) matrix at different reinforcement ratios (5, 10, 15 and 20%) to produce bio-fiber based composites. Depending on these reinforcement rates and alkali treatment, the mechanical properties of composites such as strength, elongation and modulus were investigated. The composites, which have the best mechanical properties, were selected and these composites were evaluated in terms of thermal and sound insulation with considering their morphological properties. It has been determined that artichoke stem waste fibers can provide good mechanical, thermal and sound insulation properties in the composites, and thus it has been found that great advantages can be achieved in terms of cost and ecology.

FUNCTION OF INTERCEPTION, EVAPOTRANSPIRATION AND ROOT REINFORCEMENT OF PLANT ON SLOPE STABILIZATION

The ability of plants to carry out the functions of interception, evapotranspiration and root reinforcement provides an effective and contributes to an increase in slope stability. Canopy has a role in the process of interception related to the reduction of amount the infiltrated water and the rapid fulfilment of soil moisture. Through the evapotranspiration mechanism, plants can reduce pore water pressure in the soil so that the trigger force for landslides can be reduced and the soil will be more stable. The roots mechanically strengthen the soil, through the transfer of shear stresses in the soil into tensile resistance in the roots. Roots also bind soil particles and increase surface roughness, thereby reducing the process of soil displacement or erosion. There is a positive relationship between the density of the tree canopy with the value of rainfall interception, evapotranspiration with a decrease in pore water pressure in the soil and the ability of root anchoring and binding with an increase in soil shear strength, indicating that the function of interception, evapotranspiration and strengthening of plant roots have a positive effect on increasing slope stability. Plants selection that considers the level of interception, the rate of evapotranspiration and root reinforcement by adjusting environmental and slopes conditions will determine the success of slope stabilization efforts by vegetative methods.Keywords : interception, evapotranspiration, root reinforcement, slope stabilization.

Numerical assessment of lateral distortional buckling in steel-concrete composite beams

Steel-concrete composite beams, when requested by negative moment, can fail due to Lateral Distortional Buckling (LDB), local buckling, or by the combination of these stability modes. LDB is a mode of stability in which the web must distort in order for the compression flange to displace and twist during buckling. The standard procedures that address this phenomenon use the conventional lateral-torsional buckling theories for the buckling of partially restrained beams or the U-frame model. This study investigates, through the development of refined physical and geometrical nonlinear numerical analyzes with the ABAQUS software, the strength of steel-concrete composite beams under the action of negative moment. The influences of several parameters are analyzed, such as: steel profile cross section, longitudinal reinforcement rate, unrestrained length, presence of the web stiffeners and the distribution of negative moment along the span. The results are compared with standard procedures and analytical methods. It can be concluded that the cross section and the presence of web stiffeners are the parameters that most influence the LDB strength. Regarding the standard procedures, it was found that both those who adopt the conventional lateral-torsional buckling theories and those who use the U-frame model provide conservative results. Therefore, further investigations are necessary to better understand the behavior of these elements under the action of negative moment.

Influences of reinforcement and displacement rate on microstructure, mechanical properties and fracture behaviors of cylinder-head aluminum alloy

In the present work, the material microstructure, mechanical properties and fracture behaviors of cylinder-head aluminum alloys were experimentally investigated under different displacement rates and with and without the reinforcement. By the addition of nano-clay-particles and the heat treatment, it was tried to improve mechanical properties of the base material. For this objective, after the fabrication of as-cast and nano-composite samples, respectively by gravity and stir-casting; tensile testing was done on standard samples at the displacement rate of 0.1, 1 and 10 mm/min. Then, the sensitivity analysis was performed on experimental data to find quantitatively effects of two parameters of the reinforcement and the displacement rate. In addition, the optical microscopy and the field-emission scanning electron microscopy were utilized for the microstructure and the fracture surface, plus the energy dispersive X-ray analysis. Obtained results indicated that the microstructure of the aluminum alloy was finer due to the reinforcement. Besides, both the ultimate strength and the elongation enhanced. The regression analysis implied that the strength was sensitive only to the reinforcement. Although the elongation was sensitive to both the reinforcement and the displacement rate. Investigations of fracture surfaces showed brittle behaviors with cleavage and quasi-cleavage marks.

FINITE ELEMENT ANALYSIS OF THE SHEAR BEHAVIOR OF PRESTRESSED HIGH-STRENGTH CONCRENTE PILES

By selecting suitable constitutive relations, we established 21 finite element models of prestressed high-strength concrete piles in ABAQUS. After verifying the correctness of the models, we investigated the shear span ratio, axial compression ratio, reinforcement rate of cube compressive strength of concrete and the prestressed reinforcement ratio influence parameters, such as the ultimate shear capacity of components and P−Δ relation curves. The results show that the shear span ratio has an effect on the shear performance of the piles, and that the ultimate shear capacity increases with the decreasing shear span ratio and the increasing ratio of prestressed bars. Compared with the prestressed members with ordinary reinforcement, the ultimate strength of the pile is higher, and the curve change rules under different shear span ratios are basically the same with the latter. Increasing the concrete strength can improve the shear strength of the pile, but the P−Δ relation curve at the elastic stage is almost the same. The ultimate shear capacity of the component increases with the increasing axial compression ratio.

Análise de blocos de fundação destinados ao apoio de pilares de geometria complexa

O presente trabalho tem por objetivo estudar o comportamento de blocos de fundação sobre estacas que recebem pilares de geometria complexa. Procura-se avaliar se o dimensionamento simplificado desses casos, utilizando o Método das Bielas, pode ser feito através da substituição da geometria complexa do pilar por uma seção quadrada, rotina essa frequentemente utilizada nos programas comerciais de dimensionamento automático e cercada de grandes dúvidas nos escritórios de projetos estruturais. Para tanto, foram efetuadas análises numéricas para três formatos de pilares (Retangular, em L e em C) e duas configurações de bloco (cinco e nove estacas). Na análise dos diferentes tipos de pilares, verificou-se que a consideração de geometria complexa gerou uma distribuição mais homogênea dos esforços nos blocos de fundação, resultando em campos de tração inferiores e consequentemente em menores taxas de armadura de tração quando comparados com a seção quadrada equivalente. Finalmente, para os blocos de fundação com pilares de geometria complexa investigados, verificou-se que a simplificação da geometria complexa do pilar por uma seção quadrada equivalente pode ser considerada a favor da segurança devido a maior quantidade de armaduras necessárias, validando assim a rotina normalmente adotada de maneira rotineira nos escritórios

Alkalinity and Its Consequences for the Performance of Steel-Reinforced Geopolymer Materials.

This paper investigates the development of the alkalinity and its impact on carbon steel reinforcement embedded in alkali-activated fly ashes (AAFA) and alkali-activated fly ashes with ten percentage mass (wt%) of blast furnace slag (AAFAS)-based materials (geopolymer–GP). The pH analysis of eluates indicates a remarkable decrease of alkalinity in AAFA and AAFAS in the first hours of the geopolymerization process. Phenolphthalein solution and pore solution tests on concretes also show a sharp decrease of alkalinity with increased Ca content in the binder due to carbonation. Micro X-ray computer tomography (µXCT) and electrochemical techniques indicate that the changed pH in the GP systems was accompanied by a decrease in the corrosion rates of steel reinforcement when compared to ordinary Portland cement (OPC) systems. In contrast to calcite and vaterite, which were detected in OPC and AAFAS after a carbonation process, only sodium carbonate natron was determined at lower levels in AAFA by X-ray diffraction (XRD).