Tooth Loss, Occlusal Teeth Support, Salivary Flow Rate, and Food Texture Choice in the Elderly with Cognitive Impairment: A Preliminary Study in Indonesia

Background: The elderly are at risk of experiencing oral health problems and chewing due to tooth-loss, decreased occlusal teeth support, and decreased salivary flow rate. Objective: This study aimed to compare distribution and comparison tooth loss, the proportion of occlusal teeth support, salivary flow rate, and the choice of food texture between the normal and cognitive impairment groups. Methods: Preliminary study and cross-sectional designed method on community-dwelling elderly in Bandung City, Indonesia. The inclusion criteria were no complaint of orofacial pain, not wearing denture prostheses, good communication skills, reading and writing skills, and good physical health. Demographic data include age, gender, education, and occupation. Tooth loss distribution, the proportion of occlusal contact zone, salivary flow rate, and choice of food texture were determined. Cognitive function was measured using the mini mental short examination (MMSE) form. A Mann-Whitney test was used to compare normal and cognitive impairment groups with a significance level of p-value <0.05. Results: 25 cognitive normals with MMSE score ≥25 and 10 cognitive impairment with MMSE score <25. Mean anterior tooth-loss was 2.16±3.89 vs. 4.90± 4.28 (p<0.05) and posterior tooth loss was 7.12± 5.89 vs 10.40± 4.90, p> 0.05 under normal condition compared with the cognitive impairment groups. Fewer occlusal support zone was found more frequently in cognitive impairment by groups B2, B3, B4, and C according to the Eichner Index classification. Salivary flow rate was 1.2942± 0.5768 vs 1.2755± 0.9811, p> 0.05. The participants in both groups preferred a hard-solid food portion. Conclusion: The loss of anterior teeth is significantly different. The loss of posterior teeth appeared to be different between the elderly with cognitive impairment compared with the normal groups. The occlusal support zone, salivary flow rate, and the choice of food texture as a meal served were similar between both groups in this study.

Analisis Pola Kegagalan Balok Sistem Rangka dengan Perkuatan di Daerah Tumpuan

The previous research of using truss system reinforcement in the beam without concrete (BTR) in the tension zone causes a decrease in flexural capacity due to the failure in the area near the support. Therefore, it is necessary to add tensile reinforcement in the support zone. This study aims to analyze the ultimate capacity of the truss system concrete beam strengthened with tensile reinforcement and to analyze the effect of tensile reinforcement in support zone due to crack pattern. This study was conducted experimentally in the laboratory. The dimension of truss reinforced concrete specimens are 15 cm x 20 cm x 330 cm that added tensile reinforcement with three types of length, they are BTRP 40D, BTRP 50D, and BTRP 60D, where D (13 mm) is diameter of tensile reinforcement. The flexural test is carried out by monotonic static loading. The results showed that tensile reinforcement in BTRP 40D was not able to carry the ultimate capacity due to premature failure in the support zone. while BTRP 50D and BTRP 60D specimens can enhance the ultimate capacity without facing premature failure in the support zone. The tensile reinforcement of 60D has the highest ultimate capacity because it can carry the biggest loads and minimum crack pattern.

Protection of the slab-column structures against progressive collapse

The paper presents the problem of protection of reinforced concrete slab-column structures against the occurrence of a progressive collapse caused by punching in the support zone. The experimental studies and effects of recorded collapses indicate the necessity to use the appropriate reinforcement type, which will significantly increase the load capacity of the slab-column connection after punching. One of the ways to protect the structure is to use an integrity reinforcement as the most optimal method of strengthening. The contents explain the reasons for the application and description of issues related to this type of reinforcement. The conclusions from the use of this reinforcement based on the results of laboratory tests were presented.

Hollow-Core Slabs with Reinforcement in the Support Zone

The wide use of hollow-core slabs in the construction of industrial and civil buildings is promoted by technical characteristics in the form of saving cement consumption up to 30-40 %, reducing the consumption of reinforcing steel 10 times and more, the overlap of spans up to 15-20 m. In Russia there are more than 200 plants of reinforced concrete structures producing hollow-core slabs. The technology of their production is different - from bench technology using pre-stressed forms, to the manufacture of plates on the "tracks". The main disadvantage of the use of manufactured slabs at domestic and foreign enterprises is their ability to perceive only "beam" loads. Meanwhile, giving these products the functions of operation on the console loads can significantly expand the possibility of using these effective structures. The article provides examples of amplification of hollow- core slabs operating on the console loads. Such slabs make it possible with the help of one product to create a support surface for balconies, loggias, bay windows, consoles.

Equivalent stabilizing force of members parabolically compressed by longitudinally variable axial force

The EN 1993-1-1 model of equivalent stabilizing force qd and Rd of bracings conservatively assumes that the braced member is compressed with a force constant along its length. This assumption is incorrect since the axial force distribution varies along the length of the braced member. As a result, the braced member generates equivalent stabilizing forces different from equivalent force qd and Rd acc. to EN 1993-1-1. This paper presents parametric studies of the equivalent stabilizing forces of the braced, compression top chord of roof trusses. The girder’s top chord is compressed parabolically by a variable axial force. The values of the axial compressive forces is: Nsupp in the support zone of truss and Nspan in the central zone of truss. Parametric analyses of the equivalent stabilizing force and the stress of the purlins and the bracings depending on axial forces Nsupp and Nspan in the braced member were carried out. The investigated problem is illustrated with exemplary calculations of the equivalent force in trusses.

Analytical and numerical research of equivalent stabilizing force of stiffened truss chords

The aim of this paper is research of the equivalent stabilizing forces of the braced top flange of the truss. The study takes into account the initial bow imperfection e0 of the braced top flange and the im-perfection consisting in a twist of the roof girder’s principal plane by angle ϕ0(x). Moreover, axial force N3(x) in the top flange of the truss is assumed to be longitudinally parabolically variable. The values of the axial forces is: Nsupp in the support zone of the truss and Nspan in the central zone of truss. As part of this study parametric analyses of the equivalent stabilizing forces and the stress of the bracings depending on axial forces Nsupp and Nspan in the braced member were carried out. The results are compared with the results of numerical analyses of 3D models taking the geometric nonlinearity of the structure into account.