Influence of constituents on the properties of self compacting repair materials

The paper presents the results of laboratory tests and field application in a highway bridge of self compacting repair materials. Three commercially available repair materials and one specially designed self compacting concrete were used in the study. The properties investigated were shrinkage, creep, elastic modulus and modulus of rupture. In addition, the field investigation determined flowing characteristics, compactibility and placing procedure of the flowing materials. The laboratory results show that the constituents of the mixtures greatly influence the basic properties of the materials. Inclusion of coarse aggregate in the mixture generally lowered the free shrinkage and modulus of rupture. Creep was highest in the material with polymer modification but creep recovery was lowest where large size aggregate was present. The elastic modulus was also influenced by the addition of coarse aggregate and copolymers The field results show that the materials can be placed and compacted satisfactorily without the aid of mechanical equipment

Long-term performance of high-stiffness repairs in highway structures

This paper presents the results of field monitoring of repair patches in two reinforced concrete highway bridges, Lawns Lane Bridge on the M1 and Gunthorpe Bridge across the River Trent. The repairs were applied by spraying (guniting) repair materials to compression members of the bridges. The structural members were unpropped during repair and throughout the 60 week monitoring period. The strains in the repair patches were monitored with vibrating-wire gauges. Four different repair materials were investigated whose elastic modulus was greater than that of the substrate concrete (E-rm > E-sub). The results show that efficient repairs are achieved with E-rm> E-sub, the optimum relationship being E-rm > 1.3E(sub). This enables the repair material to shed a significant proportion of its shrinkage strain to the substrate, thereby reducing restrained-shrinkage tension. It also enables the repair to attract externally applied load from the substrate in the long term. The effect of creep and shrinkage on the performance of the repair patch is also determined. Overall, the results show that current repair standards have limitations with respect to repair material specifications

Factors affecting the efficiency of repair to propped and unpropped bridge beams

This paper presents the results of laboratory and field investigations of bridge beams repaired both under propped and unpropped conditions. In the laboratory beams were repaired using hand-applied repairs. Repairs to beams in two highway, bridges were carried out using both hand-applied and flowing repairs. The repair materials used were commercial products of wide-ranging properties (shrinkage, creep and elastic modulus). Both low stiffness repair materials of elastic modulus, E-rm, less than the substrate E-sub, and high stiffness repair materials (E-rm > E-sub) were used. The repairs were applied in the tensile zone of the beams. Strain distributions in the different phases of repair patches were monitored under service loading for a period of up to 240 weeks. The results show that high structural efficiency is achieved with repairs having E-rm > E-sub, other properties (shrinkage and creep) being within reasonable limits. Such repairs ave less plane to restrained shrinkage cracking and show a capacity for load redistribution into the repair patch. Low stiffness repairs (E-rm < E-sub), on the other hand, are prone to restrained shrinkage cracking and are ineffective in load-sharing with the substrate. Repairs to propped flexural members developed erratic and non-uniform load distribution in the different phases upon reapplication of load. Composite action between the repair patch and the substrate results in cracking in the repair patch, rendering the repairs structurally inefficient

Effect of shrinkage reducing admixture on the strength and shrinkage of alkali activated cementitious mortar

The effect of a shrinkage reducing admixture (SRA) on the mechanical properties and drying shrinkage of a proprietary alkali activated cementitous material (AACM) was investigated. Five AACM mortar mixes were prepared. SRA replaced the liquid activator at a dosage of 0%, 1%, 2%, 4% and 7%. The liquid/binder ratio was 0.38. The samples were cured in water. The flexural and compressive strengths of all mixes were determined at 1day, 2 days, 7 days and 28 days and the drying shrinkage was determined up to 80 days. The results show that SRA reduced the shrinkage of AACM mortar by up to 69% after 80 days at 7% dosage. However, SRA also reduced the compressive and flexural strengths of AACM mortars. Increasing dosages of SRA reduced the compressive and flexural strength while recording less shrinkage. Regardless of the dosage of SRA, a unique relationship exists between flexural strength and compressive strength, which correlates with the data of previous research. The AACM mortar maintained strength of over 43MPa (greater than 75% of the control mix at 0% SRA dosage) at 7% SRA dosage, which is classified as high strength in accordance with British Standard PAS 8820:2016

Influence of resistivity on current and potential distribution of cathodic protection systems for steel framed masonry structures

The present paper presents the influence of resistivity on the current and potential distribution of cathodic protection (CP) systems for steel framed masonry structures. The work involves both experimental measurements and boundary element analysis and follows on from earlier experiments employing sand as a simple model for masonry encasement that has been reported elsewhere. Factors such as the size and type of masonry, moisture content and width of mortar joints will affect the resistance of the path through which the CP currents pass and thereby influence the distribution onto the steel surface. To represent such variations in resistance, it has been necessary to construct a small scale specimen replicating, as far as possible, actual applications on steel framed structures. The results from the laboratory specimen and numerical modelling are in sufficient agreement to confirm the validity of the modelling approach and allow the results to be employed for the purposes of design and development

Period dependent temperature and ambient index effects on long period fibre gratings

The ambient index and temperature effects on the spectral profiles of two sets of long period gratings (LPGs) of different periods were investigated. The shorter period LPGs were found to be more sensitive than the longer period LPGs over identical ambient index ranges but less sensitive over identical temperature ranges. The coupling wavelength shifts due to temperature are also seen to be linear and in opposite directions in each set of LPGs and unlike the ambient index shifts there seems to be no obvious modal dependency with respect to sensitivity in any individual LPG. The conclusion to this investigation is that it may be possible to design an LPG of such a period that parts of the spectral profile are unaffected by temperature whilst maintaining a reasonable ambient index sensitivity

TINJAUAN KRIMINOLOGIS TERHADAP TINDAK PIDANA INCEST DENGAN KORBAN ANAK(STUDI KASUS DI LAPAS KLAS IIA BANDA ACEH)

ABSTRAKTRI KARUNIA PUTRI AMELIA,TINJAUAN KRIMINOLOGIS TERHADAP 2015 TINDAK PIDANA INCEST DENGAN KORBAN ANAK (STUDI KASUS DI LAPAS KLAS IIA BANDA ACEH)Fakultas Hukum Universitas Syiah Kuala(v,54),pp.,bibl(Dr. DAHLAN ALI., S.H., M.Hum., M.Kn.,)Salah satu kejahatan yang sering terjadi adalah tindak pidana perkosaan. Tindak pidana perkosaan merupakan salah satu dari tindak pidana terhadap kesusilaan. Dalam Bab XIV dalam Buku II KUHP memuat kejahatan terhadap kesusilaan yang tersebar pada pasal 281 hingga 303 KUHP. Di dalamnya yang dimaksud dengan kesusilaan sebagian besar berkaitan dengan seksualitas. Salah satu jenis kelainan seksual adalah hubungan seks yang dilakukan secara paksa bersama seseorang yang masih ada hubungan darah yaitu incest, dan yang biasanya menjadi korban ialah anak-anak. Incest sebagaimana dirumuskan dalam kamus besar bahasa Indonesia adalah hubungan seksual antara orang-orang yang bersaudara dekat yang dianggap melanggar adat, hukum dan agama. Sanksi mengenai incest dengan korban anak dapat dilihat dalam Pasal 81 dan Pasal 82 Undang-Undang No. 23 Tahun 2002 Tentang Perlindungan Anak.Penelitian ini bertujuan untuk menjelaskan faktor penyebab terjadinya tindak pidana incest, dan untuk mengetahui upaya yang perlu dilakukan untuk menanggulangi tindak pidana incest di provinsi Aceh.Untuk memperoleh data dalam penelitian skripsi ini, dilakukan penelitian pustaka (library research) dan penelitian lapangan (field research) yang dilaksanakan di Banda Aceh dengan lokasi penelitian pada Lembaga Pemasyarakatan Klas IIA dengan tipe penelitian deskriptif yaitu menganalisis data yang diperoleh dari studi lapangan dan kepustakaan dengan cara menjelaskan dan menggambarkan kenyataan objek. Hasil penelitian menunjukkan bahwa faktor-faktor penyebab terjadinya tindak pidana incest adalah: Faktor rendahnya pendidikan dan ekonomi, Faktor lingkungan atau tempat tinggal, Faktor alkohol, Faktor kurangnya pemahaman terhadap agama, dan Peranan korban. Penanggulangan tindak pidana incest dapat dilakukan dengan cara mengadakan pelayanan emergency call kepada masyarakat, mengadakan pengedukasian bagi para orang tua, dan juga pembinaan mental kepada pelaku dan korban tindak pidana incest.Disarankan kepada pemerintah agar hendaknya memperbanyak wadah tempat pengaduan untuk masyarakat, serta diadakan penyuluhan hukum agar dapat menumbuhkan kesadaran masyarakat untuk benar-benar mentaati hukum. Selain itu disarankan agar sistem pembuktian dalam kasus perkosaan dapat lebih permudah, khususnya incest.Banda Ace

Analysis of interfacial shrinkage stresses in patch repairs

This paper presents simple analytical expressions that predict the interfacial shrinkage stresses in a repair patch over time. Four repair materials (L2, L3, L4 and G1) were applied by spraying (gunite) to unpropped compression members of two highway structures, and their performance was monitored to approximately six months' age. The elastic moduli of all the repair materials, E rm , were greater than the elastic moduli of the substrate concrete, E sub . The mechanics of patch repair interaction with the substrate were established, and analytical models, based on an analogy of the bimetallic strip undergoing a drop in temperature, were developed. Basic properties of the repair material (elastic modulus, shrinkage and tensile creep) and substrate concrete (elastic modulus), and geometrical details of the repair patch, are required to analyse the interfacial stresses in the repair patch. Verification of the analytical procedures is based on the field data, and the results show a satisfactory correlation between the actual and predicted stress redistribution.</p