scholarly journals Service Life Prediction of Concrete Structure Using Life-365 Software

2021 ◽  
Vol 12 (2) ◽  
pp. 1816-1826
Author(s):  
A. Deiveegan, Et. al.
Keyword(s):  
Service Life ◽  
Concrete Structure ◽  
Concrete Structures ◽  
High Strength ◽  
Vital Role ◽  
Cement Ratio ◽  
Water Cement Ratio ◽  
Global Concern ◽  
Peak Value

The performances of repaired concrete structures continue to be a major global concern. This is the improvement in repairing materials and method, several repaired concrete structures still fail, leading to costly and time-consuming. This study was conducted to assess the effect of long-term chloride penetration as well as the effect of fly ash, water-cement ratio, and inhibitor on concrete structures to predict its Service life to obtained high strength durable concrete. The water-cement ratio played a vital role, as the water-cement ratio is reducing to get more service life of the concrete and at the value of 0.5, it seems that the peak value of service life of the concrete structure. In this paper, it is generally finding the service life of a concrete structure by reviewing the previous researches and by using Software Life-365.

Microstructure of High Strength Cement Paste Systems

1984 ◽  
Vol 42 ◽  
Author(s):  
M. Regourd
Keyword(s):  
Cement Paste ◽  
Ultrafine Particles ◽  
High Strength ◽  
Interfacial Bond ◽  
Cement Pastes ◽  
Cement Ratio ◽  
Water Cement Ratio ◽  
Composite Systems ◽  
Crystalline Hydrates ◽  
Low Porosity

AbstractHigh strength cement pastes include hot pressed, autoclaved, impregnated low water/cement ratio, macrodefect free, ultrafine particles arrangement systems. The densification of the microstrucure is mainly related to a low porosity and to the formation of poorly crystalline hydrates. In composite systems like mortars and concretes, the interfacial bond between the cement paste and aggregates is moreover less porous and more finely crystallized than the normal “auréole de transition”.

Service Life of Concrete Structures

2020 ◽  
Vol 309 ◽  
pp. 267-271
Author(s):  
Milan Holicky ◽  
Jiří Kolísko
Keyword(s):  
Service Life ◽  
Concrete Structure ◽  
Limit State ◽  
Concrete Structures ◽  
Technical Specification ◽  
Working Life ◽  
Degradation Process ◽  
International Standards ◽  
Limit States ◽  
Existing Structures

The concept of service life of structures is included in international standards ISO (under the term Design Working Life), in the European document EN 1990 (Design Service Life) and in the upcoming document CEN for assessment of existing structures - Technical Specification TS (Remaining Working Life). The mentioned documents contain mainly material-independent provisions for the design and assessment of all types of structures and for any category of actions. The submitted paper includes the definition of service life (performance time) tser, which is extended for any concrete structure, considering the resistance of a structure R(t) and the effect of action S(t). Both the aggregate variables R(t) and S(t) are usually random variables significantly dependent on time t. Due to the random variability of the variables R(t) and S(t), the service life tser, needs to be related to the probability that the performance of the structure is weakened or completely eliminated. Basically, serviceability limit states (SLS) and ultimate limit states (ULS) should be considered. In the case of concrete structures another limit state corresponding to the beginning of a specific degradation process (corrosion of reinforcement), denoted tinit, may be important. In specific cases of buildings and bridges a functional (moral) service life may be taken into account. The paper includes also a practical example of assessing the remaining working life of a concrete structure.

Finite Element Analysis of High Strength Recycled Concrete Beam Flexural Properties

2015 ◽  
Vol 730 ◽  
pp. 11-14 ◽  
Author(s):  
Hai Long Zhang ◽  
Chang Chun Pei
Keyword(s):  
Finite Element Analysis ◽  
Concrete Beam ◽  
Coarse Aggregate ◽  
High Strength ◽  
Recycled Concrete ◽  
Replacement Rate ◽  
Element Analysis ◽  
Cement Ratio ◽  
Water Cement Ratio ◽  
Recycled Coarse Aggregate

By ANSYS finite element analysis we study the impact-span moment and deflection of high strength recycled concrete beam in state of initial cracking and yield with different water-cement ratio and recycled coarse aggregate replacement rate. The results showed that: 1With the increase of water-cement ratio and recycled coarse aggregate replacement rate, the deflection is on the rise. 2With the increase of recycled coarse aggregate replacement rate, the yield moment has a slight upward trend. And with the increase of water-cement ratio and recycled coarse aggregate replacement rate, the span deflection at the state of yield has a growing trend.

Short- and Long-Term Deflection of Concrete Structures

2013 ◽  
Vol 690-693 ◽  
pp. 714-719
Author(s):  
Lei Zhang ◽  
Jin Tian
Keyword(s):  
Concrete Structure ◽  
Concrete Structures ◽  
Control Methods ◽  
Short And Long Term

The general concepts of two basic forms of deflection are summarized and the existing calculation theories of deflection are introduced; two cases of concrete structure deflection, which are short-and long-term deflection, are discussed through comparison. Further, the basic theories of deflection calculation and deflection control methods are indicated based on two different cases in this paper.

Experimental Research on the Influence of Humidity on the Moisture Diffusion in Cement-Based Materials

2010 ◽  
Vol 168-170 ◽  
pp. 1806-1809
Author(s):  
Qing Su ◽  
Tie Jun Zhao ◽  
Fan Xiao ◽  
Tao Cui
Keyword(s):  
Moisture Diffusion ◽  
Moisture Loss ◽  
River Sand ◽  
Moisture Migration ◽  
Cement Ratio ◽  
Water Cement Ratio ◽  
Sea Sand ◽  
Cement Based Materials ◽  
Main Factor

The migration of ion dissolved in water is known to be main factor inducing the deterioration of porous cement-based materials in aggressive environment. Long-term tests have been carried to study the moisture diffusion in mortar with water cement ratio of 0.5 and 0.6 in different humidity, and then the inverse analysis has been done to determine the moisture diffusion coefficient D. The results indicate that the bigger water cement ratio, the faster moisture migrating in same humidity, and the moisture migration process is longer for the mortar under lower humidity. Furthermore, the results of controlled experiments carried on mortar specimens with sea sand show that the moisture migration is longer for sea sand mortar than that of river sand, and the moisture loss is bigger.

Performance Based Specifications for Durability of Mass Concrete Blocks Subjected to Harsh Arabian Gulf Marine Environment

2016 ◽  
Vol 711 ◽  
pp. 444-452
Author(s):  
K. Rahman Muhammad ◽  
Al Omran Zaki ◽  
Ibrahim Mohammed ◽  
Al Nahdi Fahad ◽  
S. Barry Mohammed
Keyword(s):  
Service Life ◽  
Arabian Gulf ◽  
Concrete Structures ◽  
Experimental Investigations ◽  
Eastern Region ◽  
Mass Concrete ◽  
Reinforcing Steel ◽  
Concrete Blocks ◽  
Durability Performance

Concrete structures in the Eastern region of Saudi Arabia are exposed to the harsh Arabian Gulf environment, and they suffer from deterioration due to accelerated corrosion of the reinforcing steel resulting in reduced service life. The service life of reinforced concrete structures in this environment is strongly affected by the quality of concrete. The resistances of concrete to chloride penetration, the chloride threshold for corrosion initiation and corrosion rate of the reinforcing steel are critical in ensuring long-term durability of concrete structures. In order to ensure that the concrete functions in the harsh environment for which it is expected to meet the service life requirement, the concrete must be designed for durability performance. A prescriptive concrete specification emphasizing on limits on mix parameters is generally ineffective for durability issues. A performance based specification based on concrete quality represented by durability indices and compliance criteria measured on cast-in-place concrete provides a framework for the contractor and ready-mix concrete supplier to produce a structure meeting the stipulated service life by the client. This paper presents the results of experimental investigations conducted for mass-concrete blocks used in the quay walls off the coastline on a reclaimed land. For long-term durability, a concrete mix in which 50% and 70% of cement was replaced by ground blast furnace slag was used to cater for the durability performance requirements.

scholarly journals The Assessment of Strength of Cementitious Materials Impregnated Using Hydrophobic Agents Based on Near-Surface Hardness Measurements

Materials ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4583
Author(s):  
Martyna Nieświec ◽  
Łukasz Sadowski
Keyword(s):  
Compressive Strength ◽  
Cement Paste ◽  
Concrete Structures ◽  
Surface Hardness ◽  
Cementitious Materials ◽  
Schmidt Hammer ◽  
Near Surface ◽  
Cement Ratio ◽  
Water Cement Ratio ◽  
The Impact

Recently, the surfaces of concrete structures are impregnated to protect them against the environment in order to increase their durability. It is still not known how the use of these agents affects the near-surface hardness of concrete. This is especially important for experts who use the near-surface hardness of concrete for estimating its compressive strength. The impregnation agents are colorless and, thus, without knowledge of their use, mistakes can be made when testing the surface hardness of concrete. This paper presents the results of investigations concerning the impact of impregnation on the subsurface hardness concrete measured using a Schmidt hammer. For this research, samples of cement paste with a water–cement ratio of 0.4 and 0.5 were used. The samples were impregnated with one, two, and three layers of two different agents. The first agent has been made based on silanes and siloxanes and the second agent has been made based on based on polymers. The obtained research results allow for the conclusion that impregnation affects the near-surface hardness of concrete. This research highlights the fact that a lack of knowledge about the applied impregnation of concrete when testing its near-surface hardness, which is then translated into its compressive strength, can lead to serious mistakes.

PERFORMANCE OF STEEL SLAG AGGREGATE CONCRETE WITH VARIED WATER- CEMENT RATIO

2016 ◽  
Vol 78 (10) ◽  
Author(s):  
Paul O. Awoyera ◽  
Olurotimi M. Olofinnade ◽  
Ayobami A. Busari ◽  
Isaac I. Akinwumi ◽  
Moyosore Oyefesobi ◽  
...  
Keyword(s):  
Steel Slag ◽  
High Strength ◽  
Tensile Tests ◽  
Normal Weight ◽  
Hardened Concrete ◽  
Cement Ratio ◽  
Water Cement Ratio ◽  
Normal Weight Concrete ◽  
Technical Details ◽  
Electric Arc Furnace Slag

Several thousands of tons of electric arc furnace slag (EAF) slag generated in Nigeria are yet to be utilised for construction; perhaps as a result of inadequate technical details for its use. The present study has evaluated the effects of varying water-cement ratio on workability and strength of locally generated steel slag aggregate (SSA) concrete. Tested samples include 150 mm concrete cubes and cylinder samples with 150 mm diameter and 300 mm height respectively. SSA was substituted in increments of 20% by weight of granite until 100% mix, while w/c was varied at 0.5, 0.55 and 0.6. Workability of fresh concrete was evaluated through slump test. Hardened concrete cubes and cylinders were subjected to compression and split tensile tests respectively, after 7, 14 and 28 days curing periods. Slump values obtained were in the range of 50 – 90 mm for all the mixes, which represented a S2 slump. Compressive strength and tensile strength increased with age and increasing slag substitution. A strength of 25 MPa for normal weight concrete was achieved at 28 days with 20% SSA substitution, only within 0.5 and 0.55 w/c ratio. However, result obtained for concrete mixes with 60% SSA and above at 28 days established that these mixes are good for production of high strength concrete.

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