Dynamic loads continue to draw the interest of structural engineers. The sources of these loads can be earthquakes, blast effects or transportation loads from railroads or highways. Especially for blast loads, terrorist attacks or military actions have caused many loses of lives and damages in several buildings. The verification of structural behavior is necessary to help designers to plan structures that support these loads and reduce damages. Although computer simulation with, specific software, have helped these designers, full-scale tests can provide valuable information about the real response of the structure. This paper presents damage diagram from ten full-scale field tests using approximately 2.70 kg of non-confined plastic bonded explosive against reinforced concrete slabs with different scaled distance, reinforcement ratio and concrete strength. The damage diagram is expected to be a help tool for designers to understand the effects of blast loads on slabs.

Explosions emanating from terrorist attacks or military weapons cause damage to civilian and military facilities. Understanding the mechanical behaviour of reinforced concrete structures subjected to blast is of paramount importance for minimizing the possible blast damage. A full-scale experimental program consisting of six reinforced concrete slabs with compressive strengths of 60 MPa, 50 MPa and 40 MPa, measuring 1.0 m × 1.0 m × 0.08 m, and subjected to 2.7 kg of non-confined plastic bonded explosive, was conducted in blast test area of Science and Technology Aerospace Department (Brazilian Air Force). This paper compares experimentally measured peak displacement values with theoretical values. Theoretical analysis was carried out using single degree of freedom (SDOF) models. The comparison showed that SDOF analysis worked very well in predicting the reinforced concrete slab peak displacement against blast effects. Qualitative analysis after the experiments showed that the blast wave shape generated by the cylindrical explosive was not uniformly distributed on the slabs for the standoff distance of 0.927 m∕kg1/3.

This paper presents results from blast tests conducted on four 50 MPa concrete slabs with reinforcement ratios of 0,175% and 0,37%. Two of the slabs were retrofitted with 50 mm thick foam in order to investigate the potential of using the foam as a strengthening option. The slabs were simply supported on two sides. Non-confined PBX (Plastic bonded explosive) was molded with the form of a cylinder measuring 20 cm in height and 10,5 cm in diameter. The explosive was detonated at 2 m stand-off distance. The equivalent TNT mass of the explosive ranges from 2,58 to 2,72 kg for the four tests. Accelerometers, displacement and pressure gages were used to measure blast wave parameters and global response of the slabs. A high-speed digital camera in conjunction with a rugged notebook recorded images. Qualitative and quantitative results are included. Slabs retrofitted with foam showed a different pressure pattern as recorded by the sensors and resulted in higher displacement, acceleration and linear momentum.

Reinforced concrete is a common construction material used to support structures around the world. However, the durability of concrete is affected by weathering action, abrasion, and chemical attack and this may lead to reduction in desired material properties necessary to support structures. Electromigration is the transport of material in a conductor under the influence of an applied electric field. All conductors are susceptible to electromigration, therefore it is important to consider the effects the electrical current resulting from the applied field may have on the conductor. The net force exerted on a single metal ion in a conductor has two opposing contributions: a direct force and wind force. Electrochemical engineering is the branch of chemical engineering dealing with the technological applications of electrochemical phenomena, such as electrosynthesis of chemicals, electrowinning and refining of metals, flow batteries and fuel cells, surface modification by electrodeposition, electrochemical separations and corrosion. This paper presents results of two small-scale tests using electromigration process as a means of transporting nanosilica to recover cement matrix integrity of aged concrete samples extracted from a 40 years old structure. A set up with two vessel was proposed, with electrical font working for 24 hours generating transportation of nanosilica into the aged concrete samples. The success of the electromigration process was verified with electronic microscope (qualitative analysis), scanning electronic microscope, and X ray dispersive energy spectroscopy. The results showed that an electromigration of nanosilica into the cement matrix occurred and resulted in reduction of micro fissures. Additionally, deposition of silica on the sample surface was observed. Reduction of calcium in the matrix was verified with the development of hydrated calcium silicate, providing the recovery of cement matrix in increasing cement mechanical properties like strength and also decreasing the porosity of the concrete matrix.

The design and evaluation of structures subjected to blast loads has increased steadily since the 11 September 2001 terrorist attacks. While shock tube testing has filled some of the data gap by replicating blast waves in a controlled fashion, there is only scant field explosion data that is easily accessible for the structural engineering community for hypothesis testing or model validation. This paper summarizes experimental design, pre-test sensor verification, and data collection from 10 reinforced concrete slabs subjected to field explosions using a modest budget. The experimental record contains pressure, displacement, and acceleration measurements of each slab except in a few cases where the sensors have failed. The data is archived at George Mason Dataverse. Following detailed description of the experimental record for each slab, an example is provided in which the data can be utilized for finite element model verification.

Predicting explosion parameters is an important step when planning for blast tests or the design of blast resistant buildings. This paper presents a comparison of recorded pressure that was reflected on the surface of reinforced concrete slabs with and without EPS (Expanded Polystyrene) foam retrofit measured from a detonation of 2.7 kg of non-confined plastic explosive. Two 50 MPa reinforced concrete slabs measuring 1.0x1.0x0.08 m, simply supported on two sides were tested. The explosive was suspended at a distance of 2.0 m from the upper surface of the slabs; one of the slabs had 5.0 cm thick foam on the top side. Eight piezoelectric pressure sensors were positioned at a distance of 2.0 m from the explosive. Results showed that the foam retrofit reduced the reflected pressure by approximately 57% when compared to the slab without EPS foam retrofit.