Concours Technicien de 3ème grade — Génie civil, option routes — Ministère de l'Équipement et de l'Eau (Morocco)

In reinforced concrete design according to BAEL 91 (Béton Armé aux États Limites), what is the design compressive strength of concrete at the Ultimate Limit State (f_bu) under persistent/transient design situations for a concrete with characteristic 28-day cylinder compressive strength f_c28 = 25 MPa? (Assume coefficient theta = 1.0 and safety factor gamma_b = 1.50).

• A14.17 MPa
• B16.67 MPa
• C21.25 MPa
• D25.00 MPa

Under the BAEL 91 relationship for concrete up to f_c28 = 60 MPa, what formula estimates the 28-day tensile strength f_t28 from f_c28, with strengths in MPa?

• Af_t28 = 0.6 + 0.06 * f_c28
• Bf_t28 = 0.2 + 0.10 * f_c28
• Cf_t28 = 0.3 * (f_c28)^(2/3)
• Df_t28 = 0.1 * f_c28

A slump test (affaissement au cône d'Abrams) on fresh concrete gives 70 mm. Under the EN 206 slump classes, which consistency class applies?

• AS1 (Firm / Ferme)
• BS2 (Plastic / Plastique)
• CS3 (Very plastic / Très plastique)
• DS4 (Fluid / Fluide)

What is the primary operational consequence of adding excess mixing water to a concrete mix on site without increasing the cement dosage (i.e. significantly increasing the Water/Cement ratio)?

• AIncreased mechanical compressive strength and reduced drying shrinkage
• BReduced compressive strength, higher capillary porosity, and increased risk of cracking
• CAccelerated setting time and enhanced impermeability to aggressive agents
• DIncreased modulus of elasticity and higher steel-to-concrete bond strength

Under BAEL 91 rules, what is the design yield strength (f_su) of high-adherence reinforcing steel FeE500 (nominal yield strength f_e = 500 MPa) at the Ultimate Limit State for fundamental load combinations (gamma_s = 1.15)?

• A400.00 MPa
• B434.78 MPa
• C476.19 MPa
• D500.00 MPa

Under BAEL 91 (Article A.7.1), what is the minimum nominal concrete cover (enrobage minimal c) required for longitudinal reinforcing bars in structural elements exposed to a marine environment or aggressive atmospheric agents (such as coastal road bridges along the Moroccan Atlantic coastline)?

• A1.0 cm
• B2.0 cm
• C3.0 cm
• D5.0 cm

A simply supported rectangular reinforced concrete beam has width b = 0.25 m, effective depth d = 0.45 m, and is made of concrete with f_bu = 14.17 MPa. At the mid-span critical section, the ultimate design bending moment is M_u = 120 kN·m. What is the value of the reduced bending moment mu_bu, and does the section require compressive steel reinforcement if FeE500 steel is used (limiting moment mu_lu = 0.392)?

• Amu_bu = 0.167; no compression reinforcement is required (singly reinforced)
• Bmu_bu = 0.285; no compression reinforcement is required (singly reinforced)
• Cmu_bu = 0.418; compression reinforcement is strictly required (doubly reinforced)
• Dmu_bu = 0.523; the concrete section must be enlarged immediately

For the beam in the previous question (b = 0.25 m, d = 0.45 m, M_u = 120 kN·m, mu_bu = 0.167, f_su = 434.78 MPa), calculate the neutral axis depth parameter alpha = 1.25 * (1 - sqrt(1 - 2 * mu_bu)), the internal lever arm z = d * (1 - 0.4 * alpha), and the required tensile steel reinforcement area A_s.

• Aalpha = 0.230; z = 0.409 m; A_s = 6.75 cm²
• Balpha = 0.167; z = 0.420 m; A_s = 5.25 cm²
• Calpha = 0.315; z = 0.393 m; A_s = 8.15 cm²
• Dalpha = 0.412; z = 0.375 m; A_s = 9.80 cm²

A reinforced concrete beam with web width b_0 = 0.25 m and effective depth d = 0.50 m is subjected to an ultimate design shear force V_u = 150 kN. If the concrete compressive strength is f_c28 = 25 MPa and the cracking is classified as 'peu préjudiciable' (unharmful cracking), what is the nominal ultimate shear stress tau_u and does it satisfy the BAEL 91 limit tau_lim = min(0.20 * f_c28 / gamma_b, 5 MPa)?

• Atau_u = 1.20 MPa; satisfies the limit of 3.33 MPa
• Btau_u = 1.50 MPa; satisfies the limit of 3.33 MPa
• Ctau_u = 2.40 MPa; exceeds the allowable threshold
• Dtau_u = 3.60 MPa; exceeds the allowable threshold

Under BAEL 91 rules, when the environment is classified as 'très préjudiciable' (highly harmful cracking, e.g. liquid-retaining structures, sewage channels, or direct exposure to aggressive industrial/marine water), what is the allowable tensile stress limitation on high-adherence steel (sigma_st_bar) at the Serviceability Limit State (ELS)?

• Asigma_st_bar = min(2/3 * f_e, 110 * sqrt(eta * f_tj))
• Bsigma_st_bar = min(1/2 * f_e, 90 * sqrt(eta * f_tj))
• Csigma_st_bar = 0.8 * f_e
• Dsigma_st_bar = min(0.5 * f_e, 150 * sqrt(eta * f_tj))

What is the primary role of a plasticizer / water-reducing admixture (plastifiant / réducteur d'eau) when added to a structural concrete mix in road or bridge construction?

• ATo accelerate the hydration reaction of tricalcium silicate (C3S) to allow demoulding wit…
• BTo disperse cement grains through electrostatic repulsion, thereby improving workability…
• CTo generate microscopic air bubbles that act as expansion reservoirs during freeze-thaw c…
• DTo neutralize alkalis in reactive silica aggregates to prevent alkali-silica reaction

In aggregate testing, what does the Los Angeles (LA) test measure?

• AThe resistance of coarse aggregate particles to fragmentation and crushing under dynamic…
• BThe resistance of aggregates to surface wear and polishing caused by vehicle tires (PSV)
• CThe percentage of clay fines present in sand determined by sedimentation
• DThe dimensional elongation and flakiness ratio of aggregate particles

What does a relatively high Sand Equivalent result, such as ES = 85%, indicate about a sand sample?

• AA very dirty, clayey sand totally unacceptable for reinforced concrete
• BA clean sand with low fine clay content, well suited for high-quality reinforced concrete
• CAn excessively pure, clay-free sand that will inevitably cause segregation and bleed wate…
• DA sand suitable only for non-structural mass concrete or backfill

In reinforced concrete beams under BAEL 91 rules, what is the purpose of the minimum reinforcement rule (condition de non-fragilité) given by A_s >= 0.23 * b * d * (f_t28 / f_e)?

• ATo ensure that the beam does not experience sudden, brittle failure upon the formation of…
• BTo guarantee that deflections under dead load do not exceed L / 500
• CTo resist torsional stresses caused by eccentric floor loads
• DTo prevent shear buckling of thin beam webs under concentrated loads

For concrete exposed to sulfate-rich soil or seawater, what is the sound cement-selection principle?

• ACPJ-35 (Portland composite cement without mineral additions)
• BSpecify a cement certified for the relevant sulfate or marine exposure and verify the com…
• CHigh-alumina aluminous cement (Ciment alumineux fondu)
• DQuick-setting masonry cement (Ciment à maçonner)

During the inspection of a cured concrete bridge deck, extensive pattern cracking ('map cracking' or faïençage superficiel) is observed on the top surface. Core sampling confirms the cracks are 1 to 3 mm deep and occurred within the first 12 hours after casting. What is the most probable cause?

• APlastic shrinkage cracking due to rapid surface water evaporation before initial set and…
• BSevere alkali-silica reaction expanding internal aggregate gels
• CPrimary load-induced flexural tension exceeding structural capacity
• DCorrosion-induced spalling from carbonation of the concrete cover

For a 30 cm x 30 cm reinforced-concrete column, BAEL defines the reduced section by removing a 1 cm strip from every edge. Using f_c28 = 25 MPa and gamma_b = 1.5, what are B_r and the unmodified concrete term B_r * f_c28 / (0.9 * gamma_b) before any slenderness reduction is applied?

• AB_r = 784 cm² and the concrete term is approximately 1,452 kN
• BB_r = 900 cm² and the concrete term is approximately 1,667 kN
• CB_r = 625 cm² and the concrete term is approximately 1,157 kN
• DB_r = 841 cm² and the concrete term is approximately 1,557 kN

What is the primary technical purpose of conducting non-destructive sclerometer (Schmidt rebound hammer) testing alongside ultrasonic pulse velocity (vitesse du son) measurements on existing civil engineering concrete structures?

• ATo obtain a combined sonreb estimation of concrete compressive strength and assess in-sit…
• BTo accurately determine the exact chemical depth of carbonation in the concrete cover
• CTo measure the electrical resistivity and active corrosion rate of the steel rebar
• DTo measure dynamic traffic load vibrations on bridge expansion joints

In direct geometric levelling (nivellement direct / géométrique), a level is setup midway between benchmark point A and station point B. The backsight rod reading at A is V_AR = 1.642 m, and the foresight rod reading at B is V_AV = 0.824 m. If the known elevation of point A is H_A = 245.500 m, what is the elevation of point B (H_B)?

• A244.682 m
• B246.318 m
• C247.142 m
• D247.966 m

In topography, the angular measurement unit 'grade' (gon) is standard across Moroccan surveying and cadastre. How many grades correspond to a right angle (90 degrees), and what is the equivalent of 1 grade in degrees?

• A100 grades; 1 grade = 0.90 degrees
• B90 grades; 1 grade = 1.00 degree
• C200 grades; 1 grade = 0.45 degrees
• D400 grades; 1 grade = 0.25 degrees

Why is the method of equal distances (principe de l'égalité des portées arrière et avant) systematically applied during precision optical levelling on civil engineering works?

• ATo eliminate residual collimation axis error, earth curvature effect, and atmospheric ref…
• BTo double the magnification of the optical telescope
• CTo ensure the levelling rod remains perfectly vertical without using a circular bubble
• DTo avoid having to take backsight readings at intermediate stations

On a topographic plan drawn at a scale of 1:1,000, two benchmark points are measured with a ruler and found to be 7.5 cm apart. What is the real horizontal distance on the ground between these two points?

• A7.5 m
• B75.0 m
• C750.0 m
• D7,500.0 m

On a topographic map with contour lines (courbes de niveau) having a contour interval (équidistance) of e = 2.50 m, the horizontal distance between two consecutive contour lines measured along the steepest slope is D = 50.0 m. What is the slope (pente) of the terrain at this location?

• A2.5%
• B5.0%
• C10.0%
• D20.0%

In road and public works surveying in Morocco, what is the definition of the 'bearing' (gisement, denoted G) of a directed survey line AB?

• AThe horizontal angle measured clockwise from the grid North (Nord Lambert / Lambert proje…
• BThe vertical angle measured between the line of sight and the horizontal plane
• CThe magnetic angle measured counter-clockwise from the magnetic North pole to line AB
• DThe astronomical azimuth measured relative to the celestial equator

A closed loop levelling traverse (cheminement altimétrique fermé) of total length L = 4.0 km is executed with an optical level over n = 16 instrument setups. The sum of backsight readings is 28.452 m, and the sum of foresight readings is 28.464 m. If the allowable closing error tolerance is T = +/- 2.5 * sqrt(L) (with T in mm and L in km), calculate the closing error f_z, determine whether the survey is acceptable, and state how the compensation should be distributed.

• Af_z = -12 mm; survey is rejected because it exceeds tolerance T = +/- 5.0 mm; must be res…
• Bf_z = -12 mm; survey is acceptable because tolerance is +/- 15 mm; distribute +0.75 mm pe…
• Cf_z = +12 mm; survey is rejected because tolerance is +/- 2.5 mm; must be resurveyed
• Df_z = +12 mm; survey is acceptable because tolerance is +/- 10 mm; distribute -0.75 mm pe…

A total station setup at benchmark station A (coordinates X_A = 500,000.00 m, Y_A = 300,000.00 m) sights target point B. The measured horizontal distance is D = 100.00 m and the bearing is G_AB = 50.00 gon (45 degrees). Given sin(50 gon) = cos(50 gon) = 0.7071, what are the Lambert rectangular coordinates (X_B, Y_B) of point B?

• AX_B = 500,070.71 m; Y_B = 300,070.71 m
• BX_B = 500,100.00 m; Y_B = 300,050.00 m
• CX_B = 500,050.00 m; Y_B = 300,100.00 m
• DX_B = 499,929.29 m; Y_B = 299,929.29 m

An optical level equipped with stadia hairs (réticule stadimétrique) is sighted horizontally at a vertical levelling rod held on a road survey point. The upper stadia hair reads L_sup = 1.845 m and the lower stadia hair reads L_inf = 1.325 m. Using the standard instrument stadia constant K = 100, what is the horizontal distance between the instrument and the rod?

• A26.00 m
• B52.00 m
• C104.00 m
• D520.00 m

When sighting a target on a bridge pier with an electronic total station, the measured vertical zenith angle is V = 96.50 gon. What is the corresponding angle of inclination / elevation (angle de site i) relative to the horizontal, and what does it indicate?

• Ai = -3.50 gon; downward sight (visée descendante)
• Bi = +6.50 gon; upward sight (visée montante)
• Ci = +3.50 gon; upward sight (visée montante)
• Di = -6.50 gon; downward sight (visée descendante)

In computing bearings from rectangular Lambert coordinates, if the coordinate differences between points A and B are Delta_X = X_B - X_A = -150.00 m and Delta_Y = Y_B - Y_A = +150.00 m, in which quadrant does the directed line AB lie, and what is its bearing G_AB in grades?

• AQuadrant 1; G_AB = 50.00 gon
• BQuadrant 2; G_AB = 150.00 gon
• CQuadrant 3; G_AB = 250.00 gon
• DQuadrant 4; G_AB = 350.00 gon

What is the primary operational advantage of using GNSS RTK (Real Time Kinematic) satellite positioning compared to total station surveying on highway alignment and earthwork projects?

• AReal-time centimeter-level 3D coordinate acquisition (1 to 2 cm accuracy) across large di…
• BComplete immunity to satellite signal masking under dense forest canopies and deep tunnels
• CSub-millimeter vertical accuracy superior to high-precision invar barcode optical levelli…
• DOperation without the need for reference base stations or network cellular/radio differen…

On a road design longitudinal profile (profil en long), why is the vertical scale typically exaggerated relative to the horizontal scale (for example, horizontal scale 1:1,000 and vertical scale 1:100, representing a 10x exaggeration factor)?

• ATo compensate for the spherical curvature of the earth over distances exceeding 500 meters
• BTo clearly visualize terrain undulations, grade changes, culvert clearances, and cut-and-…
• CTo artificially increase the apparent slope to meet minimum drainage requirements
• DTo allow earthwork volumes to be directly measured with a planimeter without unit convers…

In road cross-section drafting (profils en travers), what standard method is used to calculate the cross-sectional area of cut or fill bounded by coordinate points (x_i, y_i) of the natural ground and project template?

• AThe method of Simpson's one-third rule assuming cubic parabolic boundaries
• BThe trapezoidal coordinate method (formule des trapèzes / méthode de Gauss-Sarron): Area…
• CThe prismoidal correction formula for non-parallel end planes
• DThe Darcy-Weisbach logarithmic boundary layer integration

In horizontal circular curve setting out for a road alignment, two tangents intersect with an intersection angle alpha = 40.00 gon (36.00 degrees). If the design curve radius is R = 200.00 m, what is the tangent length T (distance from the tangent point to the vertex intersection point S), given by T = R * tan(alpha / 2)? (Note: tan(20 gon) = tan(18 degrees) ≈ 0.3249).

• A32.49 m
• B64.98 m
• C129.96 m
• D200.00 m

In computer-aided civil engineering design (such as Covadis or Civil 3D), how is a Digital Elevation Model (Modèle Numérique de Terrain - MNT) constructed from field survey data to ensure accurate earthwork calculation?

• ABy generating a Triangulated Irregular Network (TIN / réseau de triangles irréguliers) us…
• BBy calculating a simple two-dimensional moving average of spot elevations ignoring terrai…
• CBy extruding contour lines vertically without incorporating 3D survey points
• DBy applying a uniform square grid that snaps all elevations to the nearest 10-meter inter…

In the Moroccan Catalogue des structures types de chaussées neuves, what traffic measure defines classes TPL1 through TPL6?

• AThe total number of passenger cars per hour during peak morning hours
• BThe daily average number of loaded vehicles over 8 tonnes, counted in both directions at…
• CThe cumulative gross axle tonnage of all vehicles over a 50-year period
• DThe maximum legal single axle load permitted on Moroccan national highways (13 tonnes)

According to the Moroccan DRCR Pavement Design Catalogue, how is subgrade soil bearing capacity classified into soil classes St0, St1, St2, St3, and St4 based on the California Bearing Ratio (CBR)?

• ASt0: CBR <= 4; St1: CBR >= 6; St2: CBR >= 10; St3: CBR >= 15; St4: CBR >= 25, with the 4-…
• BSt0: CBR < 2; St1: CBR 2 to 5; St2: CBR 5 to 10; St3: CBR 10 to 20; St4: CBR > 20
• CSt0: CBR < 10; St1: CBR 10 to 20; St2: CBR 20 to 30; St3: CBR 30 to 40; St4: CBR > 40
• DSt0: CBR < 3; St1: CBR 3 to 6; St2: CBR 6 to 12; St3: CBR 12 to 18; St4: CBR > 18

In a standard flexible pavement structure (chaussée souple) designed under the Moroccan catalogue, what is the correct sequence of structural layers from the surface down to the natural ground subgrade?

• ACapping layer -> Sub-base course -> Base course -> Wearing course
• BBase course -> Wearing course -> Subgrade -> Capping layer
• CWearing course (Couche de roulement) -> Base course (Couche de base) -> Sub-base course (…
• DWearing course -> Capping layer -> Base course -> Subgrade

In the Moroccan pavement catalogue, what is the basic functional distinction between GNB and GNF unbound granular materials?

• AGNB is mixed with 15% Portland cement while GNF is purely clay-bound
• BGNF has a higher asphalt emulsion content than GNB
• CGNB is an unbound material used in the base course, while GNF1, GNF2, and GNF3 are unboun…
• DGNB permits rounded alluvial gravels without crushing, whereas GNF requires manufactured…

What is the primary technical purpose of conducting the Duriez test (norme NF P 98-251-1 / NM) during asphalt mix design (Béton Bitumineux) for Moroccan highways?

• ATo measure the stripping resistance and moisture sensitivity of the asphalt mix by determ…
• BTo measure the skid resistance and macro-texture of the compacted pavement surface
• CTo measure the penetration grade of the bitumen binder at 25 degrees Celsius
• DTo determine the optimum bitumen content solely from volumetric air void percentages

In the analytical pavement design method (Alizé-LCPC / Burmister multilayer elastic model) adopted in Morocco, which two fundamental strain criteria must be verified against permissible fatigue thresholds under the standard 130 kN dual-wheel axle load?

• ACompressive stress in the asphalt wearing course and shear stress in the shoulders
• BHorizontal tensile strain (epsilon_t) at the bottom of asphalt-bound layers and vertical…
• CLongitudinal thermal expansion strain and lateral centrifugal displacement
• DMaximum pore water pressure in the subgrade and shear strain at the curb interface

What primary technical difference distinguishes the Modified Proctor test (Essai Proctor Modifié) from the Standard Proctor test (Essai Proctor Normal) in road earthworks laboratories?

• AThe Modified Proctor uses a smaller mould and only 1 compacted layer
• BThe Standard Proctor applies double the compaction energy of the Modified Proctor
• CThe Modified Proctor applies a much higher compaction energy (rammer mass 4.535 kg, drop…
• DThe Modified Proctor uses hot bitumen instead of water as the compaction lubricant

During compaction quality control on a road embankment in Morocco, a nuclear density gauge (gammadensimètre) measures an in-situ wet density rho_h = 2.15 t/m³ and a moisture content w = 7.5%. What is the in-situ dry density rho_d, and what is the compaction degree (degré de compactage) if the laboratory Modified Proctor maximum dry density is rho_d_OPM = 2.05 t/m³?

• Arho_d = 2.00 t/m³; Compaction degree = 97.56%
• Brho_d = 1.95 t/m³; Compaction degree = 95.12%
• Crho_d = 2.08 t/m³; Compaction degree = 101.46%
• Drho_d = 2.15 t/m³; Compaction degree = 104.88%

In the California Bearing Ratio (CBR) test for highway pavement subgrade design in Morocco (norme NF P 94-078 / NM), why are compacted soil specimens immersed in water for 4 days (96 hours) under a surcharge weight before testing penetration resistance?

• ATo accelerate the hydration of chemical lime additives in un-stabilized soils
• BTo simulate the worst-case moisture conditions resulting from seasonal flooding, high wat…
• CTo wash out all organic matter and fine clay particles from the sample
• DTo measure the instantaneous elastic modulus under hydrostatic compression

In highway geometric design (aménagement géométrique des routes), why is a transition curve (clothoïde / clothoid curve) inserted between a straight alignment and a circular horizontal curve?

• ATo artificially increase the total length of the highway project and reduce vehicle speeds
• BTo allow the roadway width to be narrowed by 20% along curves
• CTo provide a linear variation of curvature (1/R) and allow progressive introduction of su…
• DTo eliminate the need for horizontal curve road signs and lane markings

Why is a two-lane roadway commonly given a crowned transverse profile on a tangent section?

• A0.5% slope toward the center median to collect water in an open central channel
• B1.0% flat profile with permeable asphalt surfacing
• C5.0% uniform one-way crossfall across both travel lanes
• DTo slope the pavement downward from the centerline toward both shoulders so surface water…