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"The mechanical properties and durability of high-performance concrete can be improved with the use of nanosilica. Still, the relationship between the content of nanosilica and the mechanical properties of concrete needs to be verified in order to develop of compressive strength that can be applied to any concrete mixture. The aim of this study was to develop mathematical equations that account for the relationship among concrete’s compressive strength, the modulus of elasticity with its compressive strength, and the modulus of rupture with its compressive strength. The specimens of ƒ’c80-NS10-SF5 and ƒ’c100-NS10-SF5 were fabricated by mixing natural nanosilica and silica fume, and those of ƒ’c80-NSHD5-SF5 and ƒ’c100-NSHD5-SF5 were fabricated by mixing commercial nanosilica and silica fume as the main composition materials, with the addition of other materials. The compressive strength and indirect tensile strength of the concrete were tested at 1, 3, 7, and 28 days. New mathematical models of generalized compressive strength against concrete age were empirically developed and then validated in order to derive new insights into the substitution of natural nanosilica for commercial nanosilica in the civil-engineering industry."

"This book presents the work done by the RILEM Technical Committee 227-HPB (Physical properties and behaviour of High-Performance Concrete at high temperature). It contains the latest research results on the behaviour of high-performance concretes at high temperature.The book presents the state of the art of experimental data on High-Performance concretes and it collects and synthesizes useful data about concrete behaviour at high temperatures. The book is divided into independent chapters dealing with degradation reactions in concrete exposed to high temperatures; mass transport properties; thermal properties; and mechanical properties.The results presented especially target a group of users composed by universities and testing laboratories, building material companies and industries, material scientists and experts, building and infrastructure authorities, designers and civil engineers."

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Perilaku balok prategang pratarik yang terbuat dari beton bubuk reaktif dengan kekuatan tekan di atas 120 MPa yang termasuk dalam klasifikasi beton dengan kinerja ultra tinggi diselidiki untuk mempelajari sifat fisik dan mekanik beton dan kinerja balok prategang terhadap uji beban statis. Sifat mekanik material RPC diselidiki berupa nilai kuat tekan beton, kuat tarik beton, nilai modulus elastisitas beton dan kualitas beton yang diuji dengan alat UPV dibandingkan dengan beton kuat tekan tinggi dengan kuat tekan 70 MPa. Perawatan beton saat umur awal menggunakan uap panas suhu tinggi memastikan perkembangan kekuatan tekan beton. Pengujian eksperimental dilakukan terhadap 4 buah balok pratarik yang didesain untuk digunakan sebagai balok jembatan jalan raya yaitu balok #1 (30/50-HSC-NF-S); balok #2 (30/50-RPC-F-S); balok #3 (17/50-RPC-NF-S); balok #4 (17/50-RPC-NF-S). Mekanikal properties beton RPC menunjukan nilai yang lebih unggul dibanding dengan dengan beton HSC. Dari hasil uji statis hanya balok #3 (balok RPC yang tidak menggunakan serat baja dalam adukan) yang menunjukan nilai tahanan lentur dibawah nilai teoritis akibat terjadi kehancuran getas yang terjadi pada balok. Serat baja efektif mempertahankan keutuhan balok sehingga memaksimalkan tahanan lentur, mencegah kehancuran getas yang eksplosif, dan mencegah fragmentasi beton saat beban puncak.

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The behavior of prestress pretension beams made of Reactive Powder Concrete (RPC) concrete with compressive strength above 120 MPa included in the Ultra High Performance Concrete (UHPC) classification was investigated to study the mechanical properties of concrete and the performance of prestressed beams against static load tests. The mechanical properties of RPC materials include concrete compressive strength, concrete tensile strength, concrete elastic modulus values ​​and concrete density compared to 70 MPa High Strength Concrete (HSC) concrete. Curing concrete at an early age using high temperature hot steam (steam curing) ensures the development of the compressive strength of concrete. Experimental tests were carried out on 4 pretension beams designed to be used as highway bridge beams, namely beam #1 (30/50-HSC-NF-S); beam #2 (30/50-RPC-F-S); beam #3 (17/50-RPC-NF-S); beam #4 (17/50-RPC-NF-S). The mechanical properties of RPC concrete show superior values ​​compared to HSC concrete. From the results of the static test, only beam #3 (RPC beam which does not use steel fiber in mixing) which shows a value of flexural resistance below the theoretical value due to brittle destruction that occurs in the beam. Steel fiber effectively maintains beam integrity thereby maximizing bending resistance, preventing explosive brittle destruction, and preventing concrete fragmentation during peak loads

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