93 research outputs found
Flexural Behaviour of Precast Aerated Concrete Panel (PACP) with Added Fibrous Material: An Overview
Full text linkThe usage of precast aerated concrete panel as an IBS system
has become the main alternative to conventional construction system. The
usage of this panel system contributes to a sustainable and environmental
friendly construction. This paper presents an overview of the precast
aerated concrete panel with added fibrous material (PACP). PACP is
fabricated from aerated foamed concrete with added Polypropylene fibers
(PP). The influence of PP on the mechanical properties of PACP are
studied and reviewed from previous research. The structural behaviour of
precast concrete panel subjected to flexure load is also reviewed. It is
found that PP has significant affects on the concrete mixture’s compressive
stregth, tensile strength and flexural strength. It is also found that PP
manage to control the crack propagation in the concrete panel
Fiber-reinforcement and its effects on the mechanical properties of high-workability concretes manufactured with slag as aggregate and binder
Get PDFThe feasibility of manufacturing fiber-reinforced concretes of high workability through additions of high volumes of electric arc furnace steel slag is evaluated in this paper, using sustainable binders with ground granulated blast furnace slag and ladle furnace slag as a supplementary cementitious material. An extensive experimental plan is developed to test four (self-compacting and pumpable) concrete mixtures, some reinforced with 0.5% vol. of (metallic or synthetic) fibers, in both the fresh and the hardened state. Very specific mechanical aspects are examined, such as the evaluation of both longitudinal and transversal stress-strain compressive behavior, and the assessment of direct tensile strength through the “dog-bone” test. The results of testing this sustainable concrete design yielded suitable mechanical strengths, and good toughness, ductility and impact strength, among other properties. Good adhesion between the fibers and the cementitious matrix was also evident from the fiber pull-out test results. Finally, the overall results confirmed that the use of electric arc furnace steel slag can make a real contribution to construction-sector sustainability and that the mechanical behavior of these novel concretes meets the basic design requirements for use in real structures.Spanish Ministries MCI, AEI, EU and ERDF [RTI2018-097079-B-C31; 10.13039/501100011033; FPU17/03374]; the Junta de Castilla y León (Regional Government) and ERDF [UIC-231, BU119P17]; the Basque Government research group [IT1314-19]; Youth Employment Initiative (JCyL) and ESF [UBU05B_1274]; the University of Burgos [Y135.GI] and the University of the Basque Country [PPGA20/26]. Likewise, our thanks to CHRYSO and HORMOR for supplying the materials used in this research
RHEOLOGICAL AND MECHANICAL PROPERTIES OF FIBER SELF-COMPACTING CONCRETE UNDER HIGH TEMPERATURE
No full textUse of common fibers, in addition to increasing ductility, toughness, first point cracking, and ultimate strain, plays a major role in preventing shrinkage and thermal cracks. The role of temperature in fiber bridging and change of material structure has been investigated in previous studies. Use of waste materials in structural materials can decrease further pollution of ecosystem. On the other hand, increase in oil and polymer-based waste materials, caused some concern in the international community because of the adverse environmental impact of this material. For this reason, in this research, steel fiber (0.4, 0.5 and 0.6), Polypropylene fiber (0.03, 0.05 and 0.1), and recycled Polyethylene terephthalate (PET) fiber (0.2, 0.3 and 0.4) percent of the concrete mixture volume were used. The results of the rheological (V-funnel, T50, Slump and L-Box), mechanical properties (e.g., compressive, flexural, and splitting tensile strength) and Ultrasonic Pulse Velocity (UPV) Test of self-compacting concrete exposed to temperatures of 20, 200, 300, 400, and 600^\circ showed that high contents of fibers did not satisfy some rheological and mechanical aspects of self-compacting concrete. Steel fibers increased the compressive, flexural, and splitting tensile strengths of concrete with maximum amount of 9.8\% and two other fibers cause 15\% decrease in strength of unheated specimens at most. Fiber reinforced specimens had an increase in resistance in the range of 8 to 21\% by heating specimens to 600^\circ.The flexural strength of steel fiber reinforced specimens had an increase of maximum 30\% for unheated ones. PET and P.P. fiber reinforced specimens had 9 to 20\% increase in flexural strength. The presence of fibers increases the mechanical strength, toughness, and ductility of concrete and prevents loss of strength and spalling phenomenon at high temperatures, as well as having a fundamental role in the reduction of heat, microcracks, and retaining fundamental structure of concrete
Residual strength and microstructure of fiber reinforced self-compacting concrete exposed to high temperatures
No full textEffect of Nano Silica on Mechanical Properties and Durability of Normal Strength Concrete
No full textStructural grade concrete containing expanded polystyrene beads with different particle distributions of normal weight aggregate
No full textEffects of hauling time on self-consolidating mortars containing metakaolin and natural zeolite
No full textEvaluation of reinforcement on the mechanical behavior of partially bonded fiber/matrix interface
No full textThis paper aims at introducing a new natural composite used as soil stabilizer with particular application in geotechnical engineering. The fibers introduced in the present study could be used as effective soil reinforcement. This research proves the feasibility of the use of modified jute/polypropylene in lime and cement composites and studies their effects on the tensile and compressive strength of the matrix. In general, the optimal mechanical performance of natural composites and durability depends on the optimization of the interfacial bond between natural fiber and matrix. Since the fibers and matrices are chemically different, strong adhesion at their interfaces is needed for an effective transfer of stress and bond distribution throughout an interface. In this paper a theoretical approach for the identification of elastic modulus in composite interfaces is proposed in detail with a reasonable error. The theoretical approach is based on the method using a sum of least squares criterion. The approach is applied through optimization techniques, using analytical sensitivities and correlating adhesion with Young's modulus. The validity and potentiality of the proposed technique is discussed and the results demonstrated the versatility, accuracy, and efficiency of the presented approach. The applied method also appears to be a simple way of predicting the modulus of elasticity in composite interfaces. This leads to a discussion of the most promising stabilization methods for soil reinforcement and the outlook for the future
Compressive stress-strain model and residual strength of self-compacting concrete containing recycled ceramic aggregate after exposure to fire
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